I have the Hilton American Express Business card so I'm earning base points with each purchase. Does anything happen to the points if a purchase is refunded? I'm assuming that they do since otherwise you could get free points by buying and returning things. Obviously if the return is in the same billing period it's not an issue since they haven't given the points. But what if the return is a future billing period? I was wondering if they leave the points alone since you now have a credit which will mean that you don't earn any points on purchases until you've used it up.

Also wondering if the policy is different for earned Hilton points and the base points that they're giving until the end of the year.