poor service

My phone, an alcatel onetouch idol alpha had software problems and refused to switch it on, because I bought it 4months ago it was still under warranty so I sent it for repairs to vodacom repair center on monday the 2nd of november, I was told that since it has a cracked screen even if it was working with it there they will have to bill me for fixing it. Now they gave me a qoute on friday the wednesday the 11th saying it will cost me R5100 to replace the phone because they can't fix it. Now I am confused because my phone cost me R1999 so I think its unfair that the phone will cost me R3000 than its value. I do not have that much money and now my phone will not be fixed. Please advice