Not my revenge but I was part of it.
My carer's hobby is soap making, he makes an amazing chocolate and oatmeal scrub bar. It looks just like a slice of nutty chocolate energy bar.
A work colleague had given up chocolate for lent, her relative (I think it was BIL) kept eating chocolate in front of her asking if she was missing it.
So she took the soap home and told everyone she was saving it for Easter. Everyone respected this except dick head relative who took a big bite.
I had a dispute with Morrisons.
Most supermarkets take the money from your account when you get a delivery. Morrison's don't it can take a couple of days but I didn't know that so them taking money put me over my overdraft limit and cause me to get bank charges. I don't have a lot of money so this was a disaster.
I tried going through the complaints procedure and had a couple of email saying, WE NOW CONSIDER THIS MATTER CLOSED. Yes they included the capitals.
I ordered another delivery and then cancelled the card.
They requested payment, I emailed saying they had told me on a number of occasions that the matter was closed.
They did not come back to me.