Why Am I Being Billed A Coinsurance When I Already Paid A Copay At The Time Of My Visit?

Okay so I’m not an health insurance expert by any means but my PCPs office has been confusing me for almost 2 years, and I think they have been improperly charging me. My BCBS plan only had co-insurance , no copay amount listed. Anytime I have visited my PCP I’m the past 8 months (maybe 10x) they charge me an $100 copay. They said it’s because my deductible hadn’t been met. After this, they bill my insurance for the appointment, and then charge me the full amount allowed for the appointment (since I haven’t met my deductible). The practice requires having a credit card on file and months later randomly charge me whatever amount to the card with no bill or receipt. Whenever I call to request the charges, they forward me to Billing voicemail and they never get back to me.

Is this right? If the total for the amount is $150, and they charge me this “copay” for $100, shouldn’t I only be responsible for $50? They are charging me $250 between the copay and coinsurance but only $150 is counting towards my deductible. Please help, because it feels scammy.