I have heard nothing but great things about Garmins customer service. Give them a call and from everything I have heard they will make it right. My father has a Garmin Rino that we thought he had broken by dropping it and it sounded bad. He called customer service and they talked him through (and he is not electronic oriented) checking everything out and got it working, by determining he had turned on the scramble somehow. I heard another story from a guy that had a Garmin go bad and was calling to see what he could do about it. They said they would have a new product on the way to him. He said that is great but the unit is over a year old. There was response was that didn't matter Garmin products are suppose to work and his wasn't so there would be a new one sent to him.
I hope you have the same luck.