Warped Dash Panel

I have a 2005 Prius with 31,500 miles on it. Car has been parked under car port since purchased. Also, always use Prius sun shade during hot weather. Last week I came out to drive to an appointment & discovered the corner of the passanger side dash (flat part between the glass & hard plastic) had popped up in the corner. I could not force it back in place. Had to have car inspected & went to dealer I completely trust. My main service contact said it was warped because of the heat from the windshield & tried to fix it with no luck. Had an accident 3 years ago with over $11,000 worth of damage & am sure the dash was removed/replaced. The shop is owed by my dealer & did a great job of putting it back like new. Went to them & was told it was not caused by this accident, but promised to have the factory rep check the problem when he is in town next two weeks. Repair shop had three peple look at it & took pictures. After all this rambling, has any one had a similar problem with the top of the dash buckeling & if so, what was the outcome? Thanks.

PS: This is my first post & hoped I followed procedure.