You can flatten them and glue them back in. I had to it to mine.
Set the oven to 200-225.
Put them in on a cookie sheet.
Check them every few minutes.
Once the get warm, lay them on the counter upside down and press down in the middle.
If the don't stay flat repeat the process.
If memory serves it took 4 or 5 times of pressing on them, reheating and pressing again to get them flat.