MTN - Accounts/Finance dept disaster

I have an existing contract with MTN. Last year I added an additional handset to the contract. MTN linked the handset to a different contract of mine, that is almost 10 years old, with incorrect banking details, and wrong address etc. Without checking on my ID number and seeing that I am a paying customer, MTN handed me over for collections, also reflecting negatively on my credit rating. Had to pay in large amounts to MTN just to clear my credit record. Random debit order amounts then started to go off in the middle of the month for the handset. After numerous inquiries still not resolved. After another inquiry on Monday to MTN, they inform me that an amount of R7183.62 is scheduled for debit order in this week. Apparently I requested an early termination....Which I did not! According to the call center the account is a complete mess (A ********** ) with early termination and re-activation fees charged on it.