Can I force a tenant to comply with a lease that included an Early Termination Fee if the moved without releasing interest and paying the fee?

I rented my property to a married couple for two years. The lease contained an Early Termination Clause that requires the tenants to pay a fee of $3850 to release their interest in the property and move early. They moved out in the timeframe they stated but the did not provide a forwarding address, they did not pay the termination fee, they did not sign the termination agreement releasing interest back to me and they left personal belongings in the house and there were repairs needed as well as additional cleaning required. I hold their deposit of $1925 but I have no way of sending them an invoice for deductions related to the move-out and the remaining funds from the deposit.