HTC — wrong reason given by Service center

Address:

Surat, Gujarat

I have purchased HTC one x+ half and a year ago by paying 29500.Then after 13 months It just shut off, I went to service center they told me I have to change motherboard worth Rs 17000. But I dont think there is problem in motherboard because when i keep phone charging it starts without any problem. So there may be problem in battery. Please consider this .