ESA letter

Hi, I have been receiving ESA for a number of years now. I am in the support group/ severe disability bit of it (can't remember the technical terms!) I do have savings, and deductions have been made to my ESA payments in respect of this. I have sent bank statements on an annual basis to the ESA authorities because that is what I understood I needed to do. I received letters outlining changes in their payments to me in October 2021 (following a letter and a year's worth of bank statements I sent to them by recorded delivery in Sept 2021) and again in Nov 2022 (following a letter and a year's worth of bank statements I sent to them by recorded delivery in Sept 2022) and I have been receiving reduced payments on the basis of the sums they came up with. Today, I have received a letter stating that 'Our new decision is that you are entitled to a reduced rate of ESA from 07/09/2021 to 07/11/2022. This is because your savings increased. Our new decision means you have been overpaid ESA. If the new overpayment is recoverable, a separate decision will be sent to you advising you of the amount of overpayment and why this is recoverable from you.' I haven't written to them since Sept 2022. I do not understand why I am getting this letter from them now. I received a letter from them in Oct 2021 telling me about a change in my payments that they implemented in respect of my savings bank statements for the year up to Sept 2021. I also submitted further statements in Sept 2022 for the time period between Sept 2021 and Sept 2022, which resulted in a reduction of my payments and which I received a letter about in Nov 2022. I struggle with brain fog and find managing my finances difficult. I have no idea whether their original sums were accurate in the deductions they chose to make, but my perspective is that I gave them all the information I was supposed to and they came up with a payment change on the basis of this that they implemented and which I just accepted. I have also been very careful with my money and if my savings had increased rather than reduced during the time I've had them it has been due to the combination of this and the fact I've had a few periods of being too unwell to have the weekly therapies my money usually goes towards. My income is generally less than my outgoings (despite being housebound) and my savings are also consequently already lower now than they were when they last reduced my payments. My question is, if they made a mistake with their original calculations, are they allowed to reclaim it back from me now? It was a particularly scary letter to receive to hear that I've been overpaid for 14 months, with the threat of reclaiming it from me, yet with no figures at all as to what this amount this might be, nor for the timing of this letter or understandable reasons for why they've looked at this time period again, when, as far as I was aware, they'd made a decision about my payment eligibility for this time period such a long time ago. The letter advises me to ring them if I need further info and there is the usual spiel on the back about 'what to do if you think this decision is wrong' . I wanted to get advise from you first as to my rights and then to right to them with my questions, plus copies of the letter I received from them at the time telling me about their payment decision about my savings, plus enclosing new statements indicating that I now have less savings than they think and to ask for a current payment reassessment based on this. Does this sound ok? Apparently I have to get in touch with them within one month of the date of the letter if I want to challenge the decision. I would send any letter by recorded delivery. I would prefer not to put myself through the ordeal of trying to get through to someone on the phone if at all possible because the process always exacerbates the symptoms of my health conditions. Any advice welcome, including how I might calculate for myself what they should have concluded about the payments I was owed during this time. I get confused about what gets discounted from the total balance within current and savings accounts (and at what point to measure this from in respect of ESA payments dates), partly because I also receive PIP payments. Thank you in advance for any guidance you might be able to give me with respect of any of the above.

Thanks for getting back to me on this BIS and apologies for not checking the scope of the forum properly beforehand (I saw the notice about this after I posted). Thanks for the links for the advice charities. Best wishes.

Thanks, Gary. I appreciate the extra information you give here, even though it's out of this forum's remit (and apologies for not noticing this before) Yes, I am on Income Related ESA.
I received a follow-up letter today with an amount which I am capable of paying from my savings - £130, but also an explanation for the demand that is blatantly untrue. That I failed to tell them about a change in my savings - no money went into my account between the date of my letter that I last wrote to them with bank statements (which they changed their payments to me on the basis on - so they did receive it) and the date that they are telling me that a change in my savings happened - instead, that date is the date they changed their payments to me. So a clerical error on their part about what they should be paying me-either then or now. I will write to ask for further explanation plus send further updates of my savings - which have now reduced since they were last aware. I will follow up with a welfare rights advisor as/when necessary. Thanks again for your help. I feel very fortunate to be a person who has savings and knew that I was likely to be able to afford to pay the DWP back even though there was no sums mentioned. What an unpleasant and potentially terrifying letter for them to be sending out to sick people on the basis of their own errors, though.