Really really bad service from MTN

I have been an MTN subscriber for quite a number of years and have seen how MTN's service to clients have degraded over the years. I have tried since February to upgrade my contract to a Samsung Tab A 10.5", which MTN has advertised and is still advertising. I have been to a number of MTN shops in different areas and they all say that they have no stock. I phoned the call centre 2 weeks ago and was told they would phone me back, yes sure. I logged a call on MTN's website and said I am battling to get a Tab A could they assist, the only response was that they have no stock and I should go to an MTN shop. Really? On Monday 15th April I received a call from MTN saying that my contract is due for an upgrade could they assist. I said yes please I am looking for a Tab A10.5". I was put on hold and about 2 minutes later I could hear her take me off hold and cutting the call. Damn, MTN's service is really pathetic!! I have cancelled 3 contract the last few years and I know MTN does not really care if I cancelled another one as I am only a single customer and they do not really care about their customers.