ESA and housing benefit question

i get ESA which includes my husband on my claim. in 2017 my pip renewal put me into the enhanced for both care and mobility and in 2018 i my ESA was renewed and i came out of the WRAG group and was put in the support group.
when i went into the support group we got more money from ESA, it seems that being in the support group meant that i am entitled to both types of ESA, contribution and income related.
housing benefit (and cts) sent me a very threatening letter on friday saying i have to repay a load of money as i am on only contribution based ESA and this is not a passport to full hb and cts.
but the ESA office has consistently told me that i AM on income related and entitled to free dentist, prescriptions etc - and therefore housing benefit and cts.
disability income guarantee (enhanced disability premium) and carers premium are listed on my award letter but the letter also says that my income related amount is £75.15 but because i am entitled to contribution based ESA i am paid £111.65
i just called ESA again for advice on my entitlement and was told that couples awards are ALWAYS income related, and although i am entitled to get the contribution rate (as my original claim years ago was contribution based for the first year before it changed to income related) my award is still income based because it is a couples claim, and because i am in the support group and get the disability premiums.
i went to CAB for help but they dont understand that ESA awards can be both CB and IR and say i have to repay housing benefit and cts, but i found the turn2us website and cpag say that when both are on the award then it is still a passport to full housing benefit.
i have to write to housing benefit to ask them to reconsider their decision and provide evidence and if they dont reconsider i will have to appeal - meanwhile we are financially struggling as they already reduced our hb and are sending us a bill for cts. help!

hi
i was on contribution based esa when i very first applied back in 2012. then i was on income based when i was in the wrag after the 365 days of cbased ran out.

i was put in the support group in september 2018 and it is since then that housing benefit want me to repay them some money. they say because the amount i receive is the same as for contribution based award then i am contribution based. but ESA tell me my award is income based, in fact it seems to be both, as both are mentioned on my awards letter.
so my esa claim seems to be suddenly be contribution based again, but when i ring ESA they say i am income based and entitled to free dentist, free prescriptions etc. i get the disability premiums.
the award covers both me and my husband, it is a joint award. it includes the carers premium as well as the edp.
but they deduct my husbands small occ pension, and his carers allowance from our award.
surely if i was contribution based they would not deduct anything? and i wouldnt be entitled to the edp?
ESA lady said today that because it is a couples claim it must be income related.
we do have a low income, the only other income we have apart from housing benefit and esa (not including pip) is the occ pension of 71 a week, and carers allowance of 66 per week.

yes the current claim includes the disability income guarantee at the couples rate
my husbands income is occ pension of 71 per week and carers allowance 66 per week. thats it, we have no savings and no other income other than benefits.
the most recent letter (which is for the increase in april) says:

living expenses for you and your partner 116.80
extra money because partner is a carer 37.50
disability income guarantee 24.50
support group money 39.20
giving total income related amount of 218.00
then it goes on to say that pip is not counted and
other income for household 73.60 (his occ pension assuming it goes up from 71)
carers allowance 67.25
total income is 140.85

then it says
your total income related amount is 218 - 140.85 so you would be entitled to 77.15
however because you are entitled to contribution based esa we will pay you 113.55
(we currently get 111.65 i think)

ESA sent me a letter last year when i enquired about being entitled to free dental and prescriptions - and my husband being entitled too as it is a joint claim and this letter says:

you were awarded ESA contributory; ESA income related.
claim is live and in payment. contributory payments as is the higher entitlement.

when i phoned ESA today they say i have an income based award even though they are paying me the contribution based rate, and that as its a couples claim this means it is income based anyway.

they have deducted my husbands occ pension and his carers allowance so surely it must be based on income related calculation, as when i was just contribution based in that first year they did not deduct anything at all and my husband was still working part time for part of that year before he took early retirement to become my carer.

if we have an underlying entitlement to income based ESA does this mean we are still passported to full housing benefit even though it looks like we are receiving the contribution based amount.
i found the cpag.org website and on there it says it is the entitlement that matters legally, not the 'in receipt of' that housing benefit are saying means we have to repay them.

im sorry this was a long post thank you so much for helping me