The issue will likely be on the Serve side. It should normally take around 3 business days (2 for BB), but if it doesn't after 5 business days, there' a definite problem. If I were you, I would open a dispute just in case; and if its close to your due date, arrange for alternate payment. Since BB pays late fees (up to $50) if the error is on their end, I imagine serve might as well. Also, take a screenshot of your payment from Serve, just in case it vanishes and you have to show that you made the payment on time.