Mr Price billing system have a problem with math

I am extremely annoyed. If you look on this screenshot I only have R1126.59 credit available. BUT on newest statement my outstanding balance is R3043.00. My credit limit is R8 580.00 so if I have a limit of R8 580 and I owe Mr Price R3043 I should still have available R5537 NOT R1126 as per your system. The R1 126 was the last ONLINE purchase I made, not my available balance!

Your system is totally WRONG, please forward this email to the accounts department so that they can rectify the problem. I was beyond humiliated yesterday, I was standing in your Centurion store and had a trolley FULL and my purchase was declined. I do not understand how your system can make such errors, I would advice all Mr Price customers to check their statements carefully, did your system charge the correct interest, will I be charged for the balance that is showing wrong?