I got charged by my gyno… How can I get out of it

So, I went to my gyno a month ago, she asked me if I wanted an sti test and I said yes bc why not be cautious.
I’m looking at my insurance app now, with a listing from the day I went saying I owe almost $300. It doesn’t specify for what service (doesn’t give itemized list of tests preformed) but I literally called my gyno the afternoon after my appointment in the AM, to confirm I did not owe them anything and it was in fact confirmed, that I didn’t owe anything.

So how the hell do I finesse my way out of this bc I’m a college student and that $300 would go into my savings which I care way more about than some gynecologist. Please help me lol