bad service

I went to Pep home Eastrand mall TO RETURN A phone since its not working and still under warranty, when it was taken for repairs wich took 3weeks plus, they could not fix the cell for me. they gave me new cell , on top cell was not working also same problem, when i took it back thee are problems with my refund i went there for nothing waisted my time and petrol and i told them i ned my cell im going away today now im told i need to come in again so they can call customer service , thats an internal problem why they cant call when im not there ? y must i waiste my time again to go there stand long to find out problem is not resolve this is an internal issue