I can't blame you for being insulted. To me, a promotion and increased responsibilities warrant more than what averages out to about a 57- or 58-cent raise (if you factor in a work year of 2,080 hours so it would be less for someone who is salaried and works over 2,080 hours annually). I know I would've been happy to get that raise where I am now because my position is union so it took three years before I finally got a raise (because new contract negotiations were repeatedly unsuccessful). However, about 13 years ago, I worked for a private company where I saw my coworkers (the three of us supervised a larger group; we were all the same level supervisor) get what I considered a nice raise (I think one got another $1/hr and the other $1.25). I knew my skillset was much much higher than theirs and that I worked harder than both of them, especially one (that one was always taking a break so she could talk on the phone about her side business -- she did this when management was gone for the day). I received my annual evaluation (which was quite good) and, then, in as upbeat and excited a tone he could give me, my manager told me I was getting...a 50-cent raise. I just looked at him, but I was furious. He told me that our department's director said I had "topped out" in my position, which was a lie (from her -- she didn't like me but, since I never did anything wrong, she couldn't just fire me). I resolved then and there that I would not be sticking around another year to be insulted like that while having to slave away for (which still is) the worst company I have ever worked for in my life (they did lots of illegal things to their employees, not the least of which was threaten them to keep them from talking to any authority figure outside of the company). I did resign about nine months later (and five days after the lazy coworker also resigned). To convince the remaining supervisor not to resign as well, the director authorized offering her a substantial increase of around $2/hr (see -- told you me topping out was a lie). Considering we made $29,000-30,000/yr, an additional $4,000 a year is significant.
So, if you find that this increase is not enough, you could also start looking for employment elsewhere (which is what I did -- best decision I ever made).