ABSA want me to pay for there mistake

I had more than my share with ABSA bank credit card department. I have my credit card more than five years never one problem. But boy oh boy from Feb'17 they went and moved my payment date from the first to the 20th of every month. (Please note I did not sign or phone for this to happen.) Silly me kept paying my minimum amount like always and I did not swipe my card for more than a year and a half, so you would think the amount you own will stay the same. Wrong, because ABSA decided to move my payment date, so now they want me to pay for the interest. You can explain till you blue they just keep on phoning and sms for the outstanding amount. PLEASE READ THIS: I WILL NOT PAY FOR ABSA'S MISTAKE.

They cannot provide me with any paper work or like they call it record this phone call. This will be the second time I am writing on Hello Peter. The first time someone did phone me , with no luck to fix this. So, I have little hope that this time it will help. The sorry part of all of this, is that the other department of ABSA are wonderful, like getting a loan for your new car!!!! So thank you for keeping that side of ABSA working!!!!!