Help, I was taken off Zocdoc and now being charged with out of network claims

Hi guys, so last month I booked for a dental appointment via. Zocdoc to get some general teeth cleaning close to where I live in NYC.

On Zocdoc, I booked for a doctor and made sure that this doctor was in-network with my insurance plan. But a few days later, the place called me and told me I needed to confirm my booking through them directly, and asked me to cancel my Zocdoc appointment so there’s no double booking. I figured it’s the same address so I secured my booking, then they cancelled me from Zocdoc.

On the day, I arrived, did my paperwork, I then asked the front desk girl if everything is fine and if I was in-network. She said that I was and had nothing to worry about. Later on I think she mentioned to me she only just started working there.

To start, they scanned my teeth, then after I met with another doctor, she noticed a chip to the front of my teeth and asked if I wanted to patch it. I asked her if my insurance would cover it, she said it would. So I got my general cleaning sorted, and teeth patched.

Now a month later, I’m seeing 3 claims from an out-of-network practice, $250 for scanning + $940 for the patch, and my EOB says I owe 50% of this. I feel like I’ve been robbed. What do I do now? On Zocdoc the place still advertises that my insurance is in-network.