Unsurprising

"Illustration" courtesy of:  https://www.craiyon.com "offering"

How does the math for a "charitable donation" or "tax write-off" work?  Does a means exist to take illegal or unfair advantage of either?

We have 2 or 3 questions:

• Are all "charitable donations" non-refundable or permanent from the moment a check is written or "clears" or when the relevant "tax form" is filed?
• The "policy" may or may not be "all donations are final"...
• "Policies" are or aren't non-binding "rules" or "guidelines".
• Can a "charitable donation" be refunded or returned either privately or publicly at the discretion of the "charity" or "supporter"?
• Unexpected or unsurprising things never happen when a supporter is themself the "charity".
• Who notifies the IRS (in case the relevant tax form was or wasn't filed)?
• Is every step or no step manual or voluntary?

Backward or "turn your 'slightly used' 'donation' into cash".