Why am I debited twice for R739.98 and credited once?

Again I have to complain about you guys. I emailed over a week ago, asking why my account has been in arrears from Aug/ Sep. On the history I can see, it was debited twice for an amount of R739.98 and credited once for R739.98. R600 of that amount was paid by a gift card, the rest by my account. How is this possible? All I asked for is to be contacted and this corrected. But you guys can't even do that.