Billed for HPV Vaccine, Insurance apparently doesn't cover it and costs an absurd amount

Hi, I recently got an HPV vaccine and I got charged $700 for one dose, I called my medical provider and apparently its because my insurance doesn't cover it. I am disputing with my insurance now but even so, I feel like over $700 for a dose of a vaccine is still much to pay out of pocket. What can I do in order to not have to pay the full amount or will I just have to bite the bullet?

Edit: Thanks for all the replies, I am 25 years old and live in the US so it seems like I should be covered under the ACA. I'll definitely talk with my insurance about this and see what happened.