"El Gran Magnifico"
Mr Flibble is Very Cross.
I'm thinking the luggage may have been delivered when they were there and they said it was theirs. So if they accepted delivery as theirs and won't give it back, they're stealing it - yes?
Side note: there, they're, their - did I use them all right?
You used them brilliantly. Then it would also be fraudulent misrepresentation or a crime of false pretenses (depending on FL law)