blocking of cellphone

We send in a Samsung s4 for a screen replacement (warranty claim) but we've received a bill of R1600, I've told them that I don't have money at the moment they must just leave it and send back the phone, after receiving the phone the phones network was blocked. I went back to cellc for assistance and they told me that the phone need to be send back to the repair center, the phone ne was in for 1 month, we received the phone yesterday nothing was done.after explaining again to cellc witbank we just whant the phone to be unblocked they said that it must be send back again to the repair center they said the phone is no longer on warranty and that the charges will be for my own account.the phone was away nou for 3 months and nothing was done to the phone except for cellc for blocking the phone, looks for me like cellc knew the phone is going out of warranty and just played with time to make me pay