GPX Product Suppot is Terrible

GPX KL858S 8.1 in. Under Cabinet TV Unit installed for 3 months.  Pleased with the picture and sound quality for a small unit.  Moved the screen to clean under the counter and when we replace the scereen back to a viewing position, screen went black, never to operational again.  COntacted customer service (luckily) the first time, but tehy will not answer the phone no matter how long you hold.  After 45 mintues on holding, they hang up.  I left an email on the contact website and it goes unanswered, as well.  My experience with GPX has not been positive.