garage storage tenant stopped paying rent, what to do?

[Karen F.]

We have a garage in back of a multi.  It's been rented for at least a couple of years in an oral agreement with someone who is not our tenant, for storage of his things.  He's now almost 3 months behind in the rent, knows it, and is not responding.  There is no written lease, everything was done in cash (although there are texts between us and him).  I don't know what's in the unit, but I suspect it's household goods.

With no written agreement, what are our options here?  I don't want to have to do it, but I'm fed up with chasing him for this small amount of payment, and since he has stopped responding to us, I cannot really negotiate anything with him.  Since there is no written agreement, there is no schedule of how we will dispose of his property.  Advice?