Automatic refills are working fine. But they over...

Automatic refills are working fine. But they overcharged me for one and instead of giving me credit, they charged an additional amount. Been on the phone numerous times for over 3 hours with numerous people, and no one knows what to do and how to give me a credit. Billing sends you to pharmacy who says it's a billing issue, and then sends you to customer service who says it's a billing problem, and billing says it is an issue with my co-pay from my insurance, and nothing is resolved! Different departments do not talk to each other and no one wants to do the work.