The Doctor is ... Confused

I got a bill from my (new) doctor today. "New" because I had to can my old one for being remarkably non-receptive to my telephone calls for refill prescriptions and requests for appointments. So I gave up, scoped out a new doctor, and made an appointment. "New" even though I saw him over a month ago now. Went in, talked to a guy, left, end of story... or so I thought.

The bill I received purports to bill me (and my insurance company) for a "New Patient Extended Office Visit," as well as the following lab tests: amylase, hepatitis A, hepatitis C, and lipase, and gives me a balance due (after insurance) of just under $60.

The problem? I never got blood drawn on the day I went in. These were tests that were most certainly not performed on me.

I called the office and explained that so far, the sum total of my relationship to the office was me going in, sitting down and talking with a guy who asked me all kinds of personal questions (from whether I had a family history of high blood pressure and what medications I was on to how sexually active I was including what positions I prefer), and leaving. No blood drawn means no blood work done. And, because I am an immense wuss, I would have remembered having blood drawn.

The staff of the office is quite nice. One woman called back later and explained some mix-up to me and told me it had been taken care of. She's very nice, the doctor I met with was very nice, the guy I spoke with seemed very knowledgeable and accessible, and all in all I like the practice so far as I know of it... but it just slightly concerns me that they have managed to accidentally bill me for services that clearly were not performed on me.

I'm wondering just how worried I should be.