Poor bank African Bank

African Bank is the worse bank ever. I regret opening credit with them. I have credit card with them and made arrangements to pay R50 every month. They have been deducting the R50 this month the amount went up to R2100 I don't understand how. When I can my bank they say it's a debit check. I have never made agreement for debit check of amount of R2100 our agreement was R50. This is ***** I want my money back. These are trying to revive an old credit . I open this credit in 2012 to my surprise it's still active. Every once in a while they will debit in my account. Can credit last for over 12 years. The other loan I opened at the same time with this credit card was closed