What do I have to do to have someone stop my U-verse TV from freezing?

So far, no one from AT&T has been able to stop my U-verse TV signal from freezing!  It started weeks ago when my "older" DVR receiver stopped working.  I called Technical Support and they shipped me another receiver.  I installed it and my TV worked again.  However, the signal periodically freezes.  I spoke with Technical Support numerous times, restarted various components numerous times, had two technician dispatches, replaced the DVR receiver again (was told that all of the current DVR receivers are refurbished - and apparently not vary well), replaced my router, replaced my Wireless Access Point, and still, the TV signal freezes.  I am awaiting my third technician dispatch.  I have spoken with two "managers" in the Technical Support center, who are located somewhere in central Europe.  I informed them that I want a technician who:  1) is experienced, 2) is knowledgeable, and 3) has attempted to find one of the older, not refurbished, DVR receivers.  I asked the 2nd Technical Support manager to call the technician dispatch center supervisor and ensure my three requests are complied with.  I was told that the people in the Technical Support center are unable to speak with the people in the technician dispatch center.  That is a horrible way to run an operation.  I hope the 3rd time is a charm.

(Edited to remove personal information)