Accounts department with no ears

I called Vodacom in November to reinstated the debit order and was told that my debit order would go off the end of December, beginning of January this was still not done. I called in January again and reinstated my debit order again and was told that the debit order was in place. Now the 9th Feb my phone has been cut off and Im told I owe R7000.00 how can you not get this right, i have proof of both the phone calls and SMS. Please can this be investigated and resolved and if it is not i will be laying a complaint at the Consumer protect department