About a wrongful purchase refund

My grandson, accidentally purchased a game (not entirely his fault because there was no confirmation screen, just an immediate okay we'll charge you), and I contacted Apple within minutes about it and they said they would look it over and decide. I get the decision in my favor, they said it's refunded. But 3 days now and nothing reversed in my bank. I see this is an ongoing issue reading through this forum...as big a corporation that they are, you'd think they'd get something right with all the complaints.