second iphone damage and they cant repair within t

I have sent my iphone 5 for repairs in october and apparently i was adviced cell c repairs changed the iphone another same iphone which only worked for 3 weeks and had battery problem which i than took it back to repairs and now they are sending me to the store were i got the contract to get a credit . after paying them 2477 for their previous quotation of their damaged iphone which im not even responsible for do.i just wat my phone back in a working condition cause i have paid for repairs it is within their three month warranty .