What does thick, coarse hair mean?

So I went to get my hair thinned, but the lady said to my mom that if she thinned it, then it would get even more thick. And she said that I had thick coarse hair and that she wasn't comfortable thinning it. She however did take off an inch of my hair even though we asked for three inches. She still made us pay full for it even though she didn't do what my mom asked if she could do. So, we were just wondering, what that meant.