still getting paid ESA after transferring to UC

I have recently migrated to UC however they are continuing to pay random ESA payments. I attempted to phone them which is really difficult for me and was shut down by the operator not allowing me to speak which led to me losing my temper and putting the phone down. I subsequently wrote a letter asking them to update their records to reflect I had transferred to UC as the system was still showing me as receiving ESA and thus affecting my UC payments. Several days after I had sent it I received an ESA payment and now again today I have received another ESA payment both of which are for £281.10 which seems to be around half of the rate I was initially receiving.
I just cannot deal with trying to phone them again and clearly the letter didn't work and I just dont know what to do as I suspect I will now have those 2 payments deducted from my next UC payment. I managed to put the 1st payment aside in preparation but im already struggling to manage my finances having moved from fortnightly to monthly payments and my mental health means I frequently overspend and I have no support/friends/family that can help to sort out these incompetencies.
Call me cynical but I can't help thinking they are doing it on purpose to see if I try phoning because I have said I can't manage phonecalls and exactly evidenced by my losing my temper when I tried initially. All it is doing is making me really angry and causing significant psychological trauma.

I would be grateful of any advice many thanks

I was only ever on income related as far as im aware, will have try and search all the paperwork/see what happens with my next UC calculation. im afraid I dont understand what you have said...ie does it know mean I will get UC and also the ns-esa? or will UC deduct that ns-esa? It all seems really confusing. What is the point in paying me ns-esa and then just deducting in. Will see what happens for next payment and go from there. Its just incredibly stressful. Thank you for your reply

yes that is the Contributory ESA.. I got confused about that too as I was expecting my ESA to stop 2 weeks after my submission of the form online to migrate to UC. I didnt think I would have enough to last me the 3 weeks from my last ESA payment so I asked for an advance of £250. but then I got a payment of £281 something marked as ESA also and then my statement for my first payment of UC which will be 8 August it states I still am claiming ESA.. I rang UC the guy told me to call the ESA department as they dont have the same systems. When I rang the ESA department a lovely lady explained saying I was on both Income Related and Contributory ESA (I had no idea I always thought it was income related only, so I requested a formal letter to tell me what I am getting etc) but she gave me some wrong information. She said the Contributory amount will be ontop of what I am entitled to UC.. I thought that amount then was too good to be true and had to ask her like 3 times to clarify she said YES its ontop of the £800 something i should get. So I ended up calling the help to claim line and the lady there told me NO SHE WAS WRONG! as the contributory amount i get from ESA will be deducted from the UC im entitled to. It was so stressful making all those calls and even holding for like 40 mins on one call I dont understand why they cannot work on same systems so annoying! lol