Poor customer service

I have been struggling to get a contract upgrade reversal done with MTN for a month now. The Huawei P40 lite that I purchased is not compatible with Google services and that is why I cancelled. I have been sent from pillar to post and have visited two MTN shops to help with the cancellation , and still have no joy. Endless hours spent on the phone, wasting my own airtime and promises from 1 MTN store to assist, but every day that I call, there is a different story. I have a ref number and cancellation document and I am without a new handset for a month now.