replaced DVR box for living room and lost HD

We had a short in the power line to the dvr box at the connection in the box and called to get a replacement dvr box.---service rep had me digitally sign for "new" dvr box while on the phone as she was mailing to me and I would mail back the defective one. later that day I noticed that the two bedrooms on DTA boxes would no longer function in channels 431-434, our HD channels for  ABC, NBC, CBS,and Fox-----------Also, the picture was no longer HD, and the screen now has a wide black border around the entire picture--both bedrooms after the tech signed me up for the new DVR--this has to be what caused it---I have spoken to 3 different reps to try and fix it and to no avail--they say they have tried everything---what to do next???