Uhmmmmm; something’s not right here. The OP says he has a “RT-680” (in his profile) that has only been used three times and RT won’t do anything to help.
The 680 hasn’t been made or sold new in 10+ years, so wouldn’t be supported under warranty by any stretch of the imagination. If the OP actually has a different model, purchased fairly recently, even the most jaded of us on the forum wouldn’t think RT would fail to honor its warranty. There has to be more to this story than we’ve heard to date.
Is this grill really a RT-680, or something else? Was it purchased new, or used? How long ago? Things are just not adding up at this point. There are a lot of good folks on this forum that are willing to help, but they need straight answers to do so.