Need details for MTN CEO Office

Its now 4 months that my account query with MTN remains unresolved but that doesn't seem to stop them from invoicing me every month and I gave them written notice on 09/09 that i will not renew the contract. This level of service is shocking, never mind Tim and his complaint desk because the interaction page never works. I still await his response to my mail but yet I got a feedback rating form asking me to rate the service recieved from Tim and team. Today i called the call centre again and asked to speak to the supervisior only to be told he will call me back his busy, they didnt even bother to get my numbers. Clearly this is a typical situation where big organisation trying to bully me into debt.A person can only take some much and this behaviour by MTN is clearly affecting my wellbeing. I wish someone can take up responsibility before matters get out of hand