FNB CONEX A2 CONTRACT

Good day. I have a problem with my Phone Conex A2, It doesn't charge I started reporting the problem before my contract expires (18 June) but they keep telling me that they will call me back. Its been more than 3 weeks now, I even went to the branch to report it but I am still waiting for their call. Today I called them again their report shows that I have been calling but their technical department didn't receive anything about my complain and they telling me that my contract has already expired its not their problem????