Had this happen to me a number of years ago about printer ribbons when I working IT for a travel agency.
Really busy day. In the middle of 8,000 things all of them critical and/or annoying. Got a call from a guy purporting to be a rep from our airline reservation system and indicating that we had a number of ribbons "due" us. I said "fine" not even getting a twitch on the old clue meter.
About a week later I get a call from Accounts Payable asking who gets billed for the
TWO THOUSAND DOLLARS WORTH OF PRINTER RIBBONS.
The scammers had sent a box of ribbons and invoiced us for about
TEN TIMES the amount the ribbons were worth. The invoice was a nastygram as well, indicating that payment was due immediately or "legal action would be taken" (or words to the effect).
I made a call to our CRS rep, verified it was a scam and they had nothing to do with it then sat down and typed up a "Take your fucking ribbons back, shove them up your ass sideways you ass raping thieves and if you DARE contact us or any of our branches again I'll have our lawyers wishing you were dead" letter.
Needless to say we never heard a peep out of them ever again.