gel over acrylic

I went to this place about three weeks ago and got acrylic nails. The place was great I loved it. They had a lot more nail options then any other little nail place I've ever been to and the people were really nice. So, this morning I called there to find out how much a fill would be, the lady told me 14 over the phone. But when I got there and she had already started, she asked if I had called earlier and then said that she knew she told me 14, but they have updated and improved their products, it was going to make my nails really shinny; but it costed $20 for a fill. I said okay because had already expected to pay just under that, because like I said I liked the lady and the way she did my nails, so I was going to tip her well.

Anyway, she proceded just as any other fill(as in the filing and primer) but she used a jar of liquid and a jar, self-labled, "GEL", looked like powder to me. She did everything just like you would with acrylic, but she didn't file after she applied the so called gel. then she applied something that looked like clear top coat, and had me put my hands under a uv light for three minutes, wash, and then put an other coat of polish-slighly pink topcoat.

I must admit tough, the do look really great! But after doing a little research on the internet I have a few questions. Can you even do that, put gel over acrylic? Is that even what she did? or was I scammed into paying near the price of a full set? because isn't gel in the form of gel and powder or acrylic in powder form? Has anyone ever encontered this techniqe before?

I'm just wondering because six dollars seems like a lot for her to just have me put my hands under a uv light. What bothers most and makes me suspicious is why did she tell me $14 on the phone then wait untill she had started, to tell me it was $20.

Any one with any info would be greatly appreciated! Thanx 

Thank you for your reply.

I know $14 does seem a little low, but the inital full set was like $45. I guess maybe that's their way of getting you to come back, and if you don't it's okay with them because they charged you way more, for a full set, than any other little nail shop(around here anyway). Plus, not to offend anyone in anyway, she spoke english, never touched a drill to my natural nail, the acrylic didn't have a strong odor in fact I didn't smell anything at all, and she didn't put one of those little face masks.

Anyway, thank you again for your reply. I appreciate it.