MTN Service Appaling

I have found the service levels of MTN absolutely appalling!!! Last year I decided not to take my upgrade which was due. I requested that this be left open for the upgrade to take place when I was ready. At the beginning of 2018 I went to the very same MTN store in springs mall only to be told I have upgraded - twice already. I requested to see a copy of the contract and was told they do not keep it in the store and will have to request it from head office. I then decided to route this through MTN call centre as I was not receiving any feedback on my query. I have logged two calls to no avail. every time I log a call I get a message to say my query has been resolved and closed. I am now paying for a device which I never received and seem to be hitting walls every time I try and resolve this issue. Always hearing from the MTN call centre person this was logged through the wrong department. They are quick to take their money from my account every month but not quick to sort out my query. And in the meantime someone is walking around with my upgrade. Very frustrated!!!