MTN is the worst cellphone provider

I have been trying to terminate an MTN cellphone contact. From 6 November I have been asking Hadifele Lekgetho of MTN to revise a cancellation fee quote they issued me in Sept. She referred me to MTN Retention dept. I made it clear that I couldn't get through to all MTN customer service numbers I have been given from a land line and my Vodacom number. After visiting MTN Capegate branch (and throwing my toys) I was given an account to deposit the cancellation fee to. After depositing the fee, I am now back to square one, I must now phone the same numbers I could not get through to and the branch won't assist me after 17h00...... 'because the retention dept works until 17h00'. Worse still, they refuse to give the regional manager's contact details to escalate the matter to. This is the worst service I have come across in years. I think MTN is deliberately (and *******ly) frustrating customers to discourage them from terminating contract. Their staff is taking no responsibility, obviously there are no consequences for (what in other companies would constitute) dereliction of duty. It is shocking that I struggled for weeks I could not get through to a telecommunication company?