MTN cannot allocate my payment correctly

Hi MTN

I have a number of data contracts for my business with MTN and recently I cancelled one of the contracts and changed it to a Pay as you go sim. However, I made payment to MTN and used this old number on the POP. It has been almost 2 months since I made this payment and every Monday morning, MTN cuts our data lines due to this payment as you cannot allocate it correctly. I have emailed customer care a number of times, and each time I am told that it has been forwarded and escalated with the banking department with our Account Number so that it can be allocated correctly, however this is not being done as we are still being cut off every Monday morning. We are dealing with one of your sales representatives at MTN who opens the lines every Monday morning for us and they have also emailed the customer care department a number of times (they also keep getting told that this has been escalated with the banking department). Can I please have someone competent in your banking department or customer care department who can assist us properly and get this sorted? I don't know who else to email and how many more times I need to send through the POP for the disputed amount.

Look forward to your response.

Kriszti