Issuing generic parts!

I dropped my phone a while back, which resulted in a smashed screen, I then contacted istore head office to enquire about a screen replacement, I was informed that no-one in RSA was authorized to do screen repairs and was told that I needed to take my IPhone 5 to my nearest Istore and that I would be quoted for a new phone. So on my next trip to Nelspruit we went to the Istore in Ilanga Mall and there I was told that they needed to have my phone sent away to have the damage assessed, never the less, this was done and I received a quote from Core Group a few days later. The quote was for R4311 which we paid, and it received my 'new' phone back in a white envelope, no box, no charger etc - at the time this seemed strange to me, but I had my phone so I didn't make a fuss. A week later my phone suddenly started showing 'no service' and my ' network Carrier etc had just vanished off my phone. So we took my phone back to the Istore to have them check it, and again we were told that it had to be sent away, and today, we get a call from Istore saying they won't repair the phone as it has generic parts! So I would like to know how the hell the Istore issued me a generic phone!?!?!?!?