Stylo cellphone PEP STORES

I bought a phone from Pep in Alexandra ( Stylo) after 2 days the phone was off, fortunately it happened before 7days in order for them to give me the new one, Of which I got a new one, after 14 days the phone was off again. I returned it and ot was taken for repairs and it took 2 months before I could get it. Within a month the phone is off again. And now they don't want to take it back. I am very disappointed with the service