Payment not allocated to my account

I paid an installment of R700 by eft in May and it still has not been allocated to my account. I have sent numerous emails and spoken to many call agents but no one can seem to help me. Finally it seemed like it was going to be sorted... The R700 was credited to my account, then on the same day that was reversed... So now my account still doesn't reflect the R700 I have paid 3 months ago. I don't know who else to email or phone because nothing seems to work.