Contribution- based and Income based ESA

Hi
I have recieved a letter today from DWP in regard to my employment and support allowance.
It states that following a recent change, from 14 May 2019 my employment and support allowance will be £148.20 a week.
And that from 2 July my esa will be £225.95.
I did have an assessment in March 19 via a home visit which i waited on for well over a year. Now it says im on both contribution-based and income-related esa.
If im entitled to it now, why wasnt i previously, no where within the letter does it state that this payment will be backdated. I have been in the support group for over 20 years now. I changed from Incapacity benefit to esa in 2011-2012 and me and my wife where told we were allowed £5,850 in our bank account, so our account has remained under this amount since then. I did read that Dwp owe some claiments up to £20,000. Could i be one of them.?. I have paperwork going back to the change over from incapacity to esa era. And they do now say that they have informed HMRC on their decision. Regards

Hi again Gary
I should have read this one first as you have kindly submitted more info for which you require some informational input from me, and i appreciate your quick calculation. I am still on Employment and Support Allowance of £148.20 a week. I am in the support group, i have been in the support group since Employment and Support came into being around 2011-2012.
Letter states/ We have looked at your claim again following a recent change. I had been in hospital for 9 days around March/April i am back at home now thankfully.
Perhaps the assessor at my home visit informed them of my plight, and my claim was looked at again. Letter goes on to say/ From 14th may your Employment and Support Allowance will be £148.20 a week, This is because of: a decision on your capability for work. You have been placed in the support group.
From 2 July 2019 your Employment and Support Allowance will be £225.95 a week.
You meet the eligibility criteria for Support Group. This means that you are not required to take part in any work related activityt, although you can volunteer by contacting a personal advisor. Your circumstances mean you will qualify for a christmas bonus in december of £10. We will credit you with national insurance contributions while claiming Employment and Support Allowance. The attached sheet shows how we worked out your money. If you want more information please get in touch with us.
You are entitled to Both Contribution-Based and income-related Employment and Support Allowance. This assessment is based on how much the law says you need to live on and your National Insurance contribution rrecord. The Contribution-based part of the allowance is taxable. We have advised HMRC of this decision and they may send you a revised tax code as a consequence, depending on your circumstances we will continue to crerdit you with National Insurance Contributions while you get Employment and Support Allowance. These credits can help you to qualify for benefits in the future, including your state pension. This will be paid every 2 weeks for as long as you are still entitled to Employment and Support Allowance. This isd because it is regarded as income in the calculation of your tax credits.
If we have told you in this letter that you are entitled to contribution-based Employment and Support Allowance, you may be entitled to income-related Employment and Support Allowance if you have less money coming in than the law says you need, and you satisfy the entitlement conditions for income-related Employment and Support Allowance. This means that you and your partner ( if you have one) My wife will start getting her pension around 24 june 2019. I am 3 years younger than she is. She is my paid Carer. We have savings under £3,000. I get Middle rate Care through DLA. And Lower rate Mobility also. I get Living expenses for me and my partner>>.>> Unsure about posing those details on a public forum. Extra Money because my partner is a carer. Extra money because of the disability Guarantee. Limited Capability for work addition. Extra money because you are in the upport Group which gives a total income-related amount of £214.35.
DLA-Care Comp for you/ is not counted towards Employment and Support Allowance.
DLA- Mobil Comp for you, is not counted towards Employment and Support Allowance.
Carers Allowance for Partner 66.15
Your total income £66.15.
Your income related amount is £214.35 less total income of 66.15.
So your income related entitlement is £148.20 a week. The amounts on this page apply from 14th May 2019. Then it obviously jumps to a combined total of £225.95 a week from 02/07/2019 with contribution based esa on top. Ive tried to be as clear as possible but left out some figures for privacy. Regards

Hi Gary
Thanks again for your continuing replies, they are appreciated
I think i will do what id read previously, in that i will write to the dwp. Id read that in tips on how to approach them, ie i will take a photocopy of my original documents which i have to hand, send it to them by recorded delivery, attach that recorded delivery reciept to the original documents and query the fact that they the dwp owe up to £20,000 to some claiments due to their miscalculations starting from 2014. I know by reading varies threads within this forum that they wont take anything pre 2014 into consideration. so im hopefull that they owe me money from 2014 through to the present day. I will keep you updated on my progress.
Without you guys at the helm we wouldnt know who to turn to. So in that respect im thankfull for the creation/existence of this very helpfull informational website. Keep up the fantastic work that you do guys. Regards