I've given money. When I give it, I generally relinquish the right to take it back. Just a thought.Actually, that is not true. Pay with a credit card and you can reverse the charges, I believe, for up to 5 months later.
And if you paid with PayPal, the money comes out of their account instantly.
You are describing a payment for a good or service. Donations can generally be considered different. I give to the Salvation army guy outside of the strip mall every year. I couldn’t imagine going up to the guy (or girl) this year and demanding past donations back.