Furnished apartment, tenant bought a new mattress. What to do with old one?

A tenant moved into my furnished apartment 1 month ago, if anyone stays longer than 1 year I replace the mattress so this was a new one.

They emailed saying they’ve had a new mattress purchased and delivered and if I can remove the old one I bought.

My storage is full and I have no where else to store it at the moment because I’m overseas, and no units coming free for the foreseeable future. Chucking it on marketplace and for a loss is a bit of a pain.

Kind of surprised they didn’t discuss this with me first, but here we are. Any suggestions?