Complete lack of advice and care from MTN

I recently took out a new contract with MTN stipulating that the phone must work with my Signia hearing aids. I was assured by two separate salesmen that it would and in good faith I signed the contract . However on getting home with the phone it only streamed through to my TV and not to my hearing aids or car phone. I informed them the following day and they worked on the phone and the app for an hour and a half without success. I was prepared to take out another contract and upgrade to an iphone. I was appalled by the don't care attitude as they flatly refused to take the phone back saying there was nothing wrong with it. The problem was with the incorrect advice from the staff and the fact that the phone is of no use to me the customer, and it is not what I asked for. My hearing is important to me and I am now stuck with an expensive phone and contact. I find this type of service totally unacceptable particularly as I am in my 80's and made it abundantly clear that I needed a phone which would be compatible with my hearing aids. I have been a customer with MTN since cell phones came to this country.