Sony Experia motherboard gone after 13mthns

On my cell c contract i took a sony experia in end 2014. no, 13months later the montherboard has gone and cell c just say it is my problem. I still have almost half of the 24months to go. i still pay my sony and now sony and cell c just pull up their shoulders...and it is my problem. I did nothiing to the phone to damage it, the MOTHERBOARD has gone and now it is tuff luck!! vERY VERY bad service! and i will never support them again!!