Customer Service Nightmare

I've has a contract with MTN since July the debit order has been going thru as per usual on the 1st of every month until two months ago MTN failed to collect their debit order I went to MTN (cresta) to get an explanation and they couldn't explain thinking it was a minor issue I paid cash and was promised that the issue was resolved this month on the 1st no debit order again I then called MTN (Sandton) to ask what was going on and I was told by them to contact MTN Direct to find out what the issue is only to hold and listen to a voice prompt for 30 mins at a time no one ever answered only to find that they are apparently striking. The biggest issue here is I'm in the process of buying a new car my application is being declined due to the fact that I'm a bad payer due to MTN not collecting their debit order/late payment but the money is there it has always been there MTN is just not collecting it I've been to three branches and no one is able to assist me namely Sandton, Cresta, Rosebank and Auckland Park everyone saying the same thing the system is fine I need HELP!!!!