VERY BAD credit card system

This is very very annoying seriously, the biggest mistake i have ever made, yesterday I complained here on HelloPeter about a problem I have with Game. I bought a calculator in June for R400, a month later I called for settlement amount and paid off the settlement amount. A month later I get an sms saying I must pay R134, i called 3 times trying to find out where the R134 came from and no one told me, they said it is a mistake and promised to erase it. to my surprise a month later I get yet another sms, this time the amount has increased by R37 to R171, got annoyed reported the problem on HelloPeter - got a letter from RCS confirming that my account has been settled in full and that I do not owe them anymore. JUST A DAY LATER I get yet another sms saying that I owe R80.11. ****ed as I am on the SAME DAY I call game credit card division to validate the sms I got..... GUESS WHAT? I still owe, not R134, not R171, not R80.11 but R102.30..... i so feel like screaming right now. Someone please help!!!