Here's the deal. You're NOT in a normal office situation. You are a work/study student and Jan is an employee at a school. What you have to keep in mind is Jan has probably been there longer than you and will likely be there after you graduate. Yes, it's unfair that Jan treats you a certain way ... but try to see it the other way around. How many other students have had your job over the years that Jan has been there? Now, ask yourself how many of them have been good workers vs. bad workers? How much BS has had Jan had to deal with from whiny students in the past? Chances are ... a LOT. And the turnover within the academic year is usually high so she doesn't have much of a chance to form a relationship and so she just sort of lumps all the work/study students into one. It's human nature.
I am not saying that you are a whiny student. Probably quite the opposite knowing what I know based on your presence here at TFP.
It certainly isn't fair for you to be treated a certain way based on Jan's previous experiences but if you can figure out WHY she acts a certain way you can fix the relationship pretty easily without "reporting her to a higher authority." Keep in mind that schools don't generally fire people ... ever.
The 1.5 hour lunch breaks, coming in late and general "slackerishness" are par for the course at the school I work at DURING THE ACADEMIC YEAR; but during the Summer (when students are on vacation usually) and during the breaks (which you get in Spring and Winter) the staff are usually working -- sometimes overtime depending on the department. I always have to bite my tongue when a returning student asks about my "Summer vacation." Yeah, you don't get those in the real world.
During Spring Break here I worked 60 hours making sure our email server was up to date ... then when I took VACATION last week (for my daughter's Spring Break) I worked from home for several days because that very same MF'ing email server needed more attention. M$ Exchange is a fickle bastard.
Of course, I could be completely wrong ... Jan might just be a royal bitch on a power trip.