MTN Retentions Dept. Service simply Pathetic !!!!

MTN Retentions Department’s customer service levels are really pathetic. Firstly they couriered me an Apple Iphone 8 in the incorrect colour. On their recommendation I returned the phone to by handing it to a staff member at the MTN store at the Waterfront in CT. Despite two follow-up visits to the store and numerous calls to the Retentions Dept. I am simply told ‘we will follow up and get back to you’. Nobody seems to be able to track the package and simply promises to get back to me and never does. To add insult to injury I am already being charged for the new contract ! I am unable to finalize an upgrade via the store until this existing incorrect order has been cancelled by MTN Retentions. So how do I get this issue resolved as it’s been almost a month since I returned the incorrectly supp**** phone ???