I am expected to pay after I paid up the account and requested for it to be closed!!!!!

I had an account with Mr Price for years and all was good. This year I decided that I want to pay of my account and close it. I requested a settlement letter that I struggled to get. When I finally received it I was told that I owned some money. I sent email but nothing was done instead different consultants called and sent me email to make me aware that I owe Mr Price. I decided to pay that money and requested for my account to be closed. When I sent that email I attached proof of payment to show that my account was paid off and I wanted it closed. I can tell you that today Mr Price has not closed my account and I am expected to pay up!!! Why must I do that after requesting for my account to be closed?????