Incorrect Billing

I Had a cheque account *** with standard bank up till 30.11.2015, I have sent several secure mail to standard bank asking them to close the account, to day i have received a call from MBD saying that I owe standard bank an amount of R4100. loan which i never had, when I called standard bank I was told that they had been debiting my account on monthly basis with . I do not believe that such a big bank could actually ******* an individual like me for no reasons, I refuse to pay any money to standard as I was refused an overdraft of R20 on several occasions,<br> I was declined any credit at Standard bank, and this one of the reasons that I decided to close my account,<br> if this is the how standard bank makes money, who stupid and ********* it is for a big bank to make money this way<br>