I'm just going to preface this post by saying I have never worked in retail (though my wife has), so you can take my thoughts with a grain of salt. But I am trying to put myself in the shoes of working retail.
I can somewhat understand your situation, especially if you don't really need money to get by in life. But if employment was essential, I would definitely follow any orders my boss gave, unless it was a serious safety concern. The way I see it, any position in retail (aside from management) is highly expendable. If you are working in retail, there are dozens of people out there that could fill your shoes in a heartbeat and at least one of them will be willing to work other departments for the sake of having a job. Sure, management doesn't like to pay money to hire/train new employees, but it becomes a necessary evil. My wife says the turnover rate in retail is incredible. Most folks didn't last more than six months. Yes, it's a shitty deal, but unfortunately that's the byproduct of our capitalist society and high unemployment rate.
Other posters are correct, blindly following orders in retail is likely not going to pay off in higher pay. But it will at least keep your job. Plus, that early foundation work ethic will pay dividends later off if/when you get a more professional job.
Let's face it, no matter where you work, you will occasionally be required to do work above or below your current pay grade. For example, I work in a $70k/year job in a technical field. Occasionally I get asked to do very menial jobs like file paperwork or run deliveries to clients. Most of my co-workers absolutely scoff at those requests, but I will always do them without asking any questions. I also get asked to do studies and write reports in an area that is waaay above my pay grade. This came from my parents instilling a work ethic of always doing what you are told and it will eventually pay off. Well, late last year a promotion opportunity came up in our company. Management completely overlooked the employees that refused to do menial tasks and picked the one person that would volunteer. I think you know who that person was.