Samsung S6 Repair

I purchased a new cell phone from MTN on the 18 July 2015. The speaker on the phone was faulty so I took it back for Repairs. I was then told to take it to the repair Centre at Century City, Cape Town. The phone was booked in on the 31st October 2015. I am yet to get my phone back. When I phone I am told they are waiting spares. This is the reason every week I phone. I asked to speak to a manager and to date I am still waiting for the Manager to phone me back. In the meantime MTN seem like they don't care either.