Foschini Head Office incapable of doing their work

I went to settle mY account. After payment they say I still owe R946 but my credit available is only R700. I pay R500 and the system shows I still owe R664 but my slip shows I only owe R165. Then I pay the R165 and I'm on -R0,79. Yet the system shows I still owe R664. Phoned head office and they say no but I still owe R664. The fault is on their side yet they still fight with me. Then I get statement to prove I'm right and foschini refuses to give me a letter to state that it was their fault and not mine. The staff from baywest branch was great at assisting us. Headoffice however has no clue what goes on on their system! Pathetic...