So this happened about 10 years ago while I was working at a big chain office supply store. My apologies for formatting, on mobile.
I was minding my own business stocking some shelves when a customer approaches me carrying a ream of printer paper. No big deal, people often had questions about the hundreds of different papers we carried, so I greet him.
Me: "Good afternoon, is there anything I can help you find?"
Customer: "Yeah, I'm moving and need some boxes."
Me: "Sure, I'll show you where you can get some. This way."
I take the customer over to our shipping supplies section where we sold boxes of all different sizes. The ensuing conversation and subsequent actions still has me perplexed after all these years.
Me: "Right here is where we have all of our boxes, and the tape is right over on that shelf should you need it."
Customer: "No, no, no! I'm talking about the boxes in the back that you guys crush."
Me: "Sir, I'm sorry but I can't just give you those boxes. Company policy."
Customer (getting agitated): "But you're just going to throw them out! What kind of sense does that make?!"
Me: "I don't make the rules, sir. I just have to abide by them. I can't give you something for free that we sell in the store. I can get my manager if you'd like to speak with him."
Customer (now irate): "You know what? FUCK YOU!"
As the words "fuck you" came out of his mouth, he cocked back with that ream of paper and threw it at me. I ducked to the side and luckily it only hit me in the shoulder. Before I could even react, he was storming out the front door. I was too shocked by the appalling behavior of a grown man to even say anything right away to management so he got away with one that day.
TL;DR - I wouldn't give away something we sold in store, was assaulted with a ream of paper.