Mtn my worst nightmare

Mtn really does not care about customer service. In the past 17 months I have been sending mtn an email every week over a cancelled contract I continued to be billed on for 12 months after cancellation. I have sent numerous emails for them to stop the debit order. Till today, 17 months after cancellation I still send an email every week to find out when are they refunding me. They have been ‘passing the credit’ since and nobody can tell me how far the process is. Logical next step is to lodge a case with the SA Consumer complaints or ombudsman.