incorrect cancellation amount

Hi<br> I previously complained about the service from a branch with regard to getting my cancellation fee to be paid. Then I revieved a response from MTN via this site who gave me the amount to be paid on my account . I then paid the amount . And now a few weeks later I get correspondence from Mtn saying that there's an additional amount of R1531 outstanding. I responded to the email stating the situation but no response. Today there was an UNAUTHORISED deduction from my bank of this amount paid to MTN. I am truly unsatisfied and will take this matter to the highest possible level due to the lack of competence from this service provider.