MTN - MOST CONFUSED, USELESS SERVICE PROVIDER

I have never in my life found a more confused company. I changed to account, which I have had for years, from debit order to cash. Since then they keep "losing" my payments. So when I receive an invoice, I owe R2500 even though I have paid every month. I call the call centre, they ask for POP, which I provide. Switch my phone back on then in a few days I get an sms to say ÿou have agreed to pay R2500 today" and then politely switch my phone off again!!!!! I have sent through numerous e-mails to their collections and complaints department and as it stands, 2 years down the line, I still owe them R2500. I get e-mails and sms's to say you are due for an upgrade, but when I go in to a store to upgrade, I can't because my account is in arrears. I actually dont know what to do anymore other than cancelling my contract and signing up with somone else. ALSO whatever you do, don't buy data on the app, you will not get it and then when you go into a store to show them that you have paid, but not received the data - they will say they cannot help you becaise they are not actually MTN, they are a franchise!!!!!!!!!!!!