PEP Mdantsane not helpful

I bought a Deluxe phone at Pep Mdantsane on Sat the 20/10/18 with dual sim cards. When setting up the phone the other sim card slot is not reading the sim card and when taking it back to Pep on the 22/10/18 they told me they can't take it I must call H/O. Why? Also the H/O and customer care number are not answered what's the use to call them if they are not helping? Also what am I going to do with this phone not working properly? Urgently Help!!!