Super annoyed and its unfair

I bought a cellphone in last year June,it started giving me problems,on the 16 of January 2015 I went back to the store,but without me telling the manager Tina what the problem was she told me it will cost me R350 to fix my cellphone.anyway I left the store and went back the next week.I came there and they booked in my phone for repairs but this time they didn't charge me???I then waited for 2 weeks for my phone,when it came back from repairs it was chipped ontop,so I told them I do not want the phone coz it was in a good condition when I sent it away.so I'm still waiting on my cellphone,I spoke to four consultants phoned all over the place, and they gave me a number that was alwas engaged,then the area manager Carmen called me to say that the cost of it is R600 something but because I'm waiting so long the company will cover that,that is negligence on their part not mine why should I pay?!.but my question to her was what if the phone gives me problems in future because it got chipped,she rep**** then I'll have to pay because I don't have insurance.the cellpone has a 1 year warranty why was I told it will cost me R350 in the 1st place and it was technical not my being negligent.