My DVR receiver is POSSESSED!

About 2-3 months ago I had my standard directv receiver removed and put in a DVR receiver. Everything was working great fora few days but then things started to go wrong. its ridiculous. I've never heard of anyone with problems like this. I'm supposed to be able to record 2 things at once but now it will only let me record one and I have to be watching it at the same time, which defeats the purpose of recording it. Then out of no where my recording and even live TV will cut to a channel called "directv cinema" and just play movie previews for hours on end. Sometimes after watching a recording all of the channels are black besides local stations and then sometimes I'll turn on MTV but ESPN will be playing or I'll switch it to DISNEY channel but VH1 will be on. The problem doesn't get fixed by resetting it (once in a blue moon it will work but it takes over 5 hours which is usually happening while I sleep at night and I'll wake up to it working again, but then all the same issues persist) Unplugging it and counting to 15 and plugging it back in does not work either. I've even tried to reformat it and wait almost 2 hours for it to finish, that didn't work and clearly it doesn't get fixed after 5 tech visits and the replacement of wires and a whole new box. What's more frustrating is that every other tv in this house works fine. 4 boxes total. 2 regular DVR boxes, a simple box and then a HD DVR box and mine is the only one with issues.....

Someone PLEASE PLEASE PLEASE help me!!!