Poor service

I m so frustrated by Rosebank.after written complaint about their service regarding school fees. I was phoned and the matter was escalated to relevant people.and calculations were made and I was assured that the matter will be solved.but to my surprise I m owing R1700. I have paid R8550 . because the person was telling me where was the problem yes I see that Xtra fee was removed but R1900 registration was not rectified.I m appealing to who ever that can rectify this to do so real m out of words . receipt copy for registration was made and even emailed to those who are doing accounts.but still it's not on the statement.i m not owing Rosebank instead they are the ones who are owing me R200 because R1900 for registration it's not on the current statement. Pls assist