BLACK LISTED

For nearly 2 year we have had an account with MTN for our Fibre to the home. The FTTH is great and really work well however for the duration of our contract MTN has not been able to debit our bank account and nor have they been able to institute a new debit order. Furthermore communication is nearly impossible. We have begged ,pleaded , wrote countless mails phoned and got referred from one to the next and tried everything including going to the head office, yet we still cant get this sorted out, now we are black list for not paying our account ????????WTH MTN We just want this sorted