So this happened a few years ago while I was working at a small electronics store. A customer calls in and wants a TV remote since theirs stopped working, and here is the conversation:
Me: What kind of TV is it?
Cust: An Acer
Me: looking up stock, ok we don't carry an OEM once since its at least 10 years old but we do carry a Logitech remote for $79 that will work.
Cust: Don't those $10 ones you sell work with Acer?
Me: looking at the compatibly lists, No unfortunately they don't support Acer
Cust: WHAT THE F--- I BOUGHT THE TV FROM YOU GUYS AND YOU DON'T CARRY A REPLACEMENT REMOTE?!
Me: I'm sorry but we haven't carried Acer TVs in years, they don't even make TVs anymore
Cust: WELL F--- YOU GUYS, I WILL NEVER F---ING SHOP WITH YOU AGAIN. I HAVE SPENT SO MUCH F---ING MONEY WITH YOU GUYS OVER THE YEARS AND THIS IS HOW YOU F---ING THANK ME. I HOPE YOU GUYS GO OUT OF F---ING BUSINESS!
I hang up and I burst out laughing, my co-working is looking asking "what, what?!" I explain the story and they also burst out laughing.