Bad Service

I closed my ac count with african bank and they sent me a paid up letter. It was a credit card and a loan<br> Today when i was going through my transactions i saw that African Bank deducted money out of my account. <br> I Spoke to Lebitso if I am not correct and he told me i will get a refund in 24 to 48 hours. Then i get an sms saying that i need to provide them with proof of payment, they don't even say where i must send that proof of payment to. They deducted money out of my account, the inconvenience that now i have to go to my bank and pull a statement meanwhile they see that my account is closed and they are the ones that were wrong. They know my account they deducted money out of my account which other proof do they want ?