MTN deducted R13347 instead of less than R2500 and no one is sorting my problem

I went to MTN to do Upgrade of the number that was out of contract for over 2 years. the Consultant help me and there was a fee that i was suppose to pay which was less than R500. to my suprise the bill came back with bill to R13347. I went 4 times and reopen the query that was open on my behalf from MTN Mall of Africa. but till today nothing happen and not sorted. ref *** ID ***5****1 VO MASANGU. Now am going to reverse the money R13347 and will go pay what i know i should be paying. MTN sucks