ESA mistake?

Hi, because of hearing about the mistakes made with transferring people from IB to ESA I thought I'd look into my situation. I was transferred in Feb 2013 and put into support group on contribution based ESA. I have a private pension from a divorce settlement and at that time it was about £35 a week. It increases a bit each year. I also got DLA at high rate mobility and low rate care.
Roll on to 2016 and I was transferred to PIP and got enhanced for both components. I was still on contribution based ESA support group but looking into it found out I would be better off going over to income related as I live alone so get the top ups and also for the enhanced PIP.
Anyway I rang DWP and they are telling me they have me down on their files as going from IB to income related ESA back in 2013. It was always contribution based. What I'm hoping someone can help with is, will they owe me money or will I owe them? I know it's a bit long winded but I wanted to give as many facts as possible. They are sending me a form to fill in but in the meantime I'm just concerned what all this means.
Thanking anyone in advance

Thank you for responding.
I definitely know I was transferred onto contribution based ESA. I understand that on contribution you can have up to £85 pension discounted from your income per week. My amount was about £35 per week.
What I can't work out is if I was entitled to an income related too up then how much of your pension is counted/discounted if any? Also what about disability premiums from being in the support group? Any help working it out would be good as I'm not sure even the DWP know how!

Ah I see. Thank you. So on that basis I would unlikely have been entitled to an income related too up then also?