PAYING FOR DOCTOR MISTAKE?! PLEASE HELP!?

I have been the middle person between my insurance, lab work, and primary care physician for over a month now. I am being charged for my annual blood test that should've been covered at 100% by my insurance company. I found out from the in-network hospital I went to for my blood test that I am being charged because my lab sheet requested the HIV1, RNA Quant bDNA test. I am a 100% healthy individual and am HIV negative - I was ured by my doctor that this was all routine so why not have it done on paper. I, of course, have NO IDEA what is checked on the lab sheet and trusted my doctor naturally. I am at a loss as to what to do because none of the parties are admitting fault and no corrected claim is being submitted to my insurance to clear me of these charges (over $350). Could you please give me some lead as to me whose fault this is? I also found out that the HIV1, RNA Quant bDNA test should ONLY be done on HIV positive patients. Why did the lab people go ahead with this test if they already knew I was HIV negative? Please advise! Thank you so much!