This incentivizes abusive behavior by users who want refunds, and cheapens the cost of abusive behavior. This mechanism was discussed in relation to OnlyFans somewhat recently -- creators that wanted to ban abusive "fans" had to refund them. (Unfortunately, I don't have a link handy.)
The problem here is that Facebook couldn't tell OP had been impersonated by an abuser -- as you say, "actions outside the user's control."