Tenant Wants to Break Lease Early

[Cory St. Esprit]

We lease a small commercial space to a non-profit to use for their thrift shop. They serve veteran women who deal w/ substance abuse and homelessness. They were a tenant when I purchased the building and we all signed an Assumption of Lease under new ownership. Tenant just informed me they plan to vacate the property tomorrow (so, 24 hours notice) due to "the business growing and the space now being too small for their needs." They have a lease in place through 9/30/25 (so about 19 more months). My lawyer and I have already looked over the lease in the past and there is zero clause for breaking the lease early. By her assumption, they need to pay up. We knew the tenant was kind of thinking about moving and we let them see about finding another business to sublet (they couldn't find anyone). 

I'm thinking of suing for the $28,500 in rent we should receive in rent...but they're playing the "we're a non-profit serving veterans..." so either I am out $28,500 or I sue and become the guy who hates women veterans. My main gig is I own 28 Subway restaurant franchises, including in this town and if that's the rumor they want to spread, I'm fearful of the fall out to my restaurants. Thoughts, ideas?