Dissatisfaction with MTN services

I'm deeply disappointed at MTN's service delivery and support to clients. 3 weeks ago I contacted the call centre with the query that I was unable to access my billing for September as they have now migrated to a new billing system. 4 calls later and 1 email (no response), I have not had my query resolved nor have they followed up with my query. Each time I was told there is an error on the system and they were unable to email me a copy of my invoice, their parting shot was that they have now escalated my query to their support/billing dept. to rectify the error. 3 weeks later I have still not received a courtesy call nor has the error been rectified. The one consolation is that my contract comes to an end at the end of October, so I will by that time have made a decision to cancel the contract after being with MTN for over 20 years.