music choice channels don't work

The music choice channels are unusable.  All the channels skip or break up and the picture has lines and blocks moving around.  This has been going on for months.  A few months ago I got a new TV box and it still happens.  A tech came out 10 days ago and said my equipment was fine and it may be Xfinity equipment on my street.  He would put in an order and they would come out in about a week.  I heard nothing.  I called this tech and now he says it is not the physical equipment.  It is a 'system' issue.  It would have to be fixed in the corporate office or the network?  He has no idea when there will be a fix - it could be a month or more!!  I am paying a ton of money to not receive 50% of what I want with this service.  I have had comcast tv for almost 40 years and have always had no problem getting the music channels just like all the other channels.  I need a contact person in corporate to help me get this fixed asap.