Pepcell give me a working phone i paid for

I bought a hisense u40lite mobile phone. There are ni internet settings according to my network service provider for the phone and they suggest i take it back.

According to Pepcell the cant take the phone back but they sold it to me without those settings.

I have recieved communication from Hisense and MTN regarding this complaint but not Pepcell after i sent them all emails

I just want a working phone thats all i paid for

C Moloto ***