Poor Customer Service

My upgrade was done in July, I received the incorrect Phone. On the same day, I called MTN and was told to return it to their nearest branch. on the 24th of July, the phone was sent. I called MTN gave them the IRMS number. To this day, I have not received my new phone. Every time I call, I was told some1 will call me back. Lindo(manager) promised that this will be sorted. Still nothing. My account was debited for the full amount of the new upgrade including insurance.