Customer Care ZERO rating

Customer Care ZERO rating. On 10/06/2019 I agreed to an upgrade of a cell phone over the phone and specifically requested that A black unit be delivered. On 18/06/2019 a white unit was delivered, I sent the unit back with the couriers and eversince then I have been SPECTACULARLY unsucessful at getting the upgrade model delivered. Since the 18th June I have phoned many times and I feel I have spoken to every department in MTN but each time my problem is not resolved but SOMEONE from MTN is going to call me back to help me. But NO ONE phones me back. I have been billed for the new cell phone (that I don't have). My level of frustration is extremely high. I feel the MTN has no consideration for their customers and the level of CUSTOMER CARE is extremely poor with no one taking responsibility for the performance of their jobs. Much better to hand the problem to someone else-also the managers do that. Custome Care ZERO rating.