Pep poor service

Good Morning I'm highly disappointed from the service I got a from Pep cell4310 in Westgate centre shop number ***. Bought a new cell phone on Saturday brought the phone the next following day due to it doesn't support the the apps that I'm using in order for me to work because I work with a phone and the phone I bought from Pep is no use to me, now the ladies in the store are refusing exchange the phone, I DDnt want a refund I jst want to take another phone but for the poor service that I got clear shows me they jst wanted my money than no service for me, im so angry I left the phone in the shop yesterday because the phone is useless Nd I'm get a poor service from the store. Can this matter be sorted ASAP

LESEGO ***