Unacceptable and Dishonest Practices!

We had a loan with African bank for an amount of R12000+, over the past 2 years that loan has been paid, when I phone the call center to find out how far the loan amount it's as if I haven't been paying at all! How can a R12000+ loan be on R10000+ after 2 years???!!! That is just down right dishonest from African bank! to add to that I was so upset and frustrated that I asked for a settlement amount last week, the amount was calculated at R12676, that's the amount i took the loan out for!!! REALLY!!! I then paid the amount to get rid of the loan, African still debited my account at the end of August, I called and said they must refund the money because I settled the loan. The agent said that would be arranged and it will take 3-5 business days. I called today as a follow up on that reversal and was told it won't happen. Mind you I paid R24000+ to settle a R12000+ loan after 2 years, which still had 1 year left!!!!!! That is absolutely disgusting and unacceptable that I am not getting refunded cause according to them they didn't add the August installment to the settlement amount. That is shocking!!!!! Then you have the nerve to call me yesterday to offer me a credit card!! Really?!