How old were they before frozen? You need to add the amount of days they were around before being frozen originally.
You can re-freeze again but it will change their texture.
Also give them a smell test before cooking. If the cryovac package is expanded or they smell funky throw them out.
If you have some Patent Pending TendRub however that will bring them back to life
Maybe TendaRub should get it's own forum section