MTN suspending my service when I have paid

I have paid my account, sent them 10 emails with the proof of payment, but they keep suspending my service saying I owe them money, I paid more than it was but they cannot find or allocate the payment. Which is nonsense because I have the proof of payment from my bank. Calling MTN customer care is a waste of time as they don't answer or cut you off. Once again they cut me off, I have lost 3 jobs because of this and have been onhold for about 40 minutes and then get cut off.