Should I Complain?

I've been having serious problems with my shifts, etc at work lately. I work part-time and am a full-time student in my final year. But recently I've been getting a lot of pressure from my Shift Manager to work more hours during the weekend, etc. He keeps apologising about it, but the problem is we have a new guy from Head Office in our establishment and he's insisting to the shift manager that I'm just being difficult, should be working more, etc.
My Shift Manager came up to me yesterday and said that I should be able to work more because there's a Bank Holiday coming up, as well as Easter. He told me the Head Office bloke told him to give me more shifts because I would have that time off. I already said that I don't have Easter holidays and am too busy with college work to take up any more shifts, which my Shift Manager said he knew, but he had to put me down on the schedule or he'd get into trouble. He said it would be ok and I could just not show up. But that would look bad on my part!
I'm getting really annoyed. I have a thesis to submit in May as well as exams and I do not need to be hastled by some big-headed idiot from Head Office who doesn't even have the guts to face me himself. I feel sorry for my Shift Manager having to play middleman, but I can't agree to anything just so he doesn't get into trouble. I work two days a week during my college year and have done so for the past three years and it has never been a problem until this new guy showed up. I seriously want to complain to Head Offices about this, because it is completely unreasonable. With all this drama I've gotten to the point where I don't even care if I lose my job - in fact it would probably be a relief, and if the Head Office guy ever decides to speak with me directly I'm going to tell him to leave me alone or I'll walk out. I'm sick of it. I don't need it.
Sorry I'm ranting a little, but do you guys think my complaint is reasonable? Should I take it to Head Office? Or are there other things I could do before I go that far? What would you do?