I know the feeling all too well
I know this suggestion will sound even more ridiculous but if you are a regular visitor of your own town/city centre then drop by at your local HMRC office. When I did this I was even more frustrated when I was given an ID ticket with a desk and telephone but I got through to someone immediately who knew exactly what they were talking about without holding for an answer and no transferring to another dept.
Like I say, I know it sounds like messing about but I was in & out the office in less than 3 minutes for something I had just spent nearly an hour on trying to arrange.
I've just registered myself for the government gateway (for accessing my personal information and making amendments, doing reports online etc). Only adding this info for people who need to contact them more often. I haven't started using it so cant say if its any good yet.