The boomerang gifter
What would prompt a hardened Scrooge to actually spring for a gift? Why, the guarantee that he could return it and get his money back!
You were genuinely touched by the generosity of your penny-pinching best friend when you opened the gift he gave you. It was something you always wanted, that you'd both admired. But wait. What's that? Oh, no! It's broken! And the gift is gone as quickly as it arrived.
Your friend vows to exchange it for a new, undamaged one. He may even offer an initial progress report: "They're, uh ... back ordered." But you'll never actually see it again.
And you'd never be so boorish as to inquire, would you? Of course not. The Boomerang Gifter is counting on your good manners.