Bad service from The Executive office of MTN

Over the course of the the last 4 months MTN have managed to disable my voicemail on 3 separate occasions. The last version of this says \this number is not available on the MTN network"when you call me and it goes to voicemail. I have emailed the CEO twice and have been dealing with Jay Govender after he told me to deal directly with him after my 2nd episode. Well version 3 ( the current one ) has been going on since 27 May and all I have had is one email response from him since then. I am at a loss what to do as no one answers in the call centre due to the industrial action. I would move to Vodacom immediately if I wasn't tied into a contract. MTN you should be ashamed at how your loyal customers are being treated. Continue this way and and there won't be any subscribers left to give shocking service to."""