Repairs took 2 months and the same issue returns

In October 2017, I purchased a Huawei Mate 10 Pro from MTN. In September 2018, I took my phone in for repairs. For months, I had been struggling with it. The microphone (or so I assume) was broken. I could hear people calling me, but they couldn't hear me. Voice notes wouldn't record, videos would have no sound.

It took MTN close to 2 months to repair my phone. This was after they had told me it would take 3 weeks at most. They told me that the part was out of stock and they had ordered it. This was only after I had called them to find out how the repair was going. If a repair is running late, I would honestly have appreciated a notice.

And now, in January 2019, I am having the same problem. I cannot call people, they cannot call me. I can't record anything that requires sound.

Two months to repair a phone and now three months later that repair proves to be useless?