NHS. Part time.
I was employed to do A. A being a very specific admin role. I changed the way A was done to make it more efficient and ended up with capacity.
I was then given B to do. I didn’t mind as I had the time and the person who’s job it was was snowed under with work.
Someone left and I was given C to do. C had nothing whatsoever to do with me. I was asked if I would do it short term as a favour. This was 6 months ago. C is now the main thing I do with A&B on the side.
A month ago I was given D to do. D is so widely out of anything I am employed to do it isn’t funny. It’s a completely separate job all on its own. And much much bigger than it was made out to be.
C is 1 band above my pay grade.
D is 2 bands above my pay grade.
On top of all this is do a mish mash of adhoc pieces of work which people give me as its “in my wheelhouse” 
A month ago I requested a meeting with my manager and they agreed to give back some of the work. I emailed them a week later to tell them I would contact the people it was going back to and they said to wait as they needed to talk to them. I’ve had two emails ignored since then and I still have all the work with me.
I am literally doing 3 peoples work on part time hours, being paid less money than the people who are employed to do it. I went above my line manager and they said talk to your manager. I said I had, they said they would speak to them. Didn’t hear another word and they’ve ignored the last email I’ve now sent them.
What the hell do I do here? I’ve also applied for two other roles in the same trust. Not even been given an interview which absolutely stinks as they are less responsibility than I have now. My application was checked by a senior manager who is also a friend and they couldn’t understand why I hadn’t been shortlisted either.
I’m being screwed here aren’t I?