Pathetic service and no results

I tried to upgrade one of my Mtn contracts 4 months ago. After a long delay and no feedback from Mtn, I cancelled the upgrade. Since then I have been billed for a contract and a phone that I do not have. I have several references on trying to get the contract returned to its original top up contract status, a credit passed and a refund. After spending several hours on the phone with their call centre, retelling my story over and over, I was told that the contract has been rectified, a refund will be paid and my billing will be sorted out, nothing has happened and they debited my account again with the inflated cost of a contract and phone I do not have.<br> I get sms's regularly to go to my nearest Mtn outlet to upgrade my handset. How does one branch of Mtn not know what another branch is doing? <br> I can't get a number to contact a supervisor or manager at Mtn directly to sort this issue out. Is the only recourse now legal action??