MTN, I NEED YOUR URGENT ASSISTANCE

The phone I have with MTN on contract (under insurance, too) can't be used anymore because the microphone does not work anymore. I have been trying to get some assistance from MTN at Village Mall to either have it repaired (under insurance) or upgrade. They said I should wait until 01-02-2019 as I would then be able to upgrade. On the date, they had no stock. I asked them to please order stock. When I phone again today, MTN head office in Centurion said they don't know when they will get stock. Does MTN not understand the urgency? I have been patiently waiting for a solution to this phone where NOBODY can hear me when they call for two weeks now. Please, I also use my phone for business and my clients are getting extremely angry at me for not answering or answering and not being able to hear me. They don't believe me anymore! I need a different phone and I am due for an upgrade... Can you not just help me, MTN? Please....! I beseech, implore and beg you for assistance here. Even though I am not supposed to. Vodacom can help me immediately (as per communication with them), but first I need to get the contract cancelled and pay the cancellation fee/balance. But I'd rather have MTN assist ASAP.