Tenants moving out early....do I return their deposit.

[Megan Arzt]

I have tenants who just signed a year lease as of March 1st.  Now they bought a house and are moving out after only 3 months.  I specifically state in my lease in bold that "if the lease is broken for any reason (this includes leaving early) then the security deposit will not be returned."  

I mentioned this to them and now they are threatening to take me to small claims court as well as call the state of Utah for over a dozen violations (no idea what if these are made up - they won't tell me).  If I am in any violation I would want to fix them.  Also, they haven't moved out yet, so they could do damage to the house.

In their defense, they did pre-screen some tenants and find me a replacement.  I did have to spend about 10 hours checking references as it took applications to find suitable candidates.

I will have no break in tenancy.  I don't want to start a fight, but what is the reason for having a year lease if tenants never abide by them?  I have only had 3 tenants out of dozens who have finished out a lease here in Moab.  My Colorado property has never had this problem.

I want to do the right thing and would love advice from both the legal and the ethical side.

Thanks!