Replacement Cellphone Problems

I have a contract insured under the MTN Insurance package, which, as it turn out, is outsourced to Monitor SA, which, in turn, uses Budget Cellular to supply and repair the insured devices in the event of theft or damage. Budget replaced my device with a supposedly new one after an insurance claim in August 2019. This device is clearly not new, since on the DSTVNow app it brings a message that it was registered by a previous user. In addition, the bluetooth and GPS does not work. I have sent the device in to them twice in a row without success. Now they have resorted to ignoring my complaints.