Disappointed by Pep Cell Midway Crossing

Pep cell in Midway Crossing, I bought a phone in November late or December early from this store through Pay Joy. After a month or so it just stopped working, I then sent it back and that was in January, first week. Till this day it never came back from repairs. The guy who assisted me firstly refused to take it back because I lost one of three slips. I fought in order for him to take back the phone. I think I am being punished because they said it should be back within 30 days. He is refusing to give the contact for repair company saying they don't have.