BCBS Overpayments/recoupments

Does anyone have experience with overpayments/recoupments with BCBS MA? In other states I’ve worked with, they will send a letter with brief explanation of the overpayment and options to dispute. With MA, I have never seen a notification. They occasionally put on an EOB what they intend to recoup with no explanation or appeal options, we call claims and they aren’t very helpful, and then they recoup money. Does anyone know the process, who to call and how to prevent recoupments?