Shop Fee???

I recently had my car aligned in a local dealer's garage. First of all, I had an appointment with the Chevy garage but the guy who does the alignments was sick that day I had the appointment. Since I had had the appointment for a week, they took it to the Ford garage to have it done. They are both owned by the same company. I had a quote from the Chevy garage and went with them over some of the independent guys because they were a few dollars cheaper. Anyway, I knew there were going to be a few extra things they needed to do like put on a tie rod and perhaps an axle with the boot. When the called to ask me if they could do those things, I said yes, do whatever needs to be done for the least amount of money you can do it. I went down to pay my bill and they were $5 more on the alignment than the Chevy garage but OK. Then I see a $10 misc charge. I asked them what that was for. "OH, it is just a shop fee. We put it on every ticket. It is a percentage of your bill." I ask, "What is it for?" "It is just a shop fee." Again, "What is it for?" At this time they started to get very impatient and I think, rude, "Well, it is for shop supplies." Me:"Isn't that the parts charge?" They: "NO, that is for the parts." ME:"Isn't that included in the labor fee?" Which by the way is $75 an hour. They: "NO, it is for things like" and I am telling the truth."ELECTRICITY, and oil and shop rags."
I am not kidding. I think they should have said coffee and rolls. Anyway, I think that should be included in the quote of price because that made them much higher than the independent guy. If they need to do it then they should put it on the labor charge and I would not know how to question it.