Motor Razy 3xx cellphone

Hi,
We bought the Razr 3xx 1 month ago. The screen does not come on. We can make and receive calls but cannot see screen.  At&t said the phone had water damage because when opening the back of phone a red dot indicator was on.  This phone has not had water damage.  They told me I could send the phone to Motorola for a repair fee of $75.00.  Have you heard of similar problems with this phone.
Many thanks