I accidentally sold my grandma’s ashes at a garage sale… how do I fix this?

So, I was cleaning out the house and had a bunch of random stuff for sale. Apparently, someone thought my grandma’s urn was a vintage decorative vase and bought it for $5. I only realized it was missing when my mom asked why Nana was no longer on the mantel.

Obviously, I can’t just ask for it back like a normal person. That would be too easy. I need the worst possible way to fix this. Should I stage a fake haunting and scare them into returning it? Post a Craigslist ad saying it’s cursed? Buy it back at an absurdly high price but in small, dramatic increments?

Help me make this an even bigger disaster.