Received dental work I didn't want. I told them I didn't want uncovered procedures, they did it anyways.?

Recently, I went for a dental checkup. When the dental assistant was about to give me x-rays, I told her I didn't want any procedures that weren't covered. She seemed to take note of it. Then about 10 minutes later she was giving me $200 worth of x-rays that weren't covered, which I discovered when I received my bill. She told me AFTER the fact when I called to inquire that knowing what the insurance covered was my responsibility. This seems like a total scam that a professional would do something like this. Do I have a leg to stand on to dispute this?
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It's pretty bad business, but the insurance is your responsibility. A dental office deals with so many different plans and coverages, it's impossible to know what's covered and what's not covered for each individual. You have to stay on top of it, not the dental office.
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