Tenants left after 1st month, what do I do with the deposit?

[Robert Berth]

We are in Jacksonville, FL. We rented a property to a couple, after the first month they split up. The guy left and the lady stayed for a month while she searched for a new place. She told us that she needed to move out because she didn't have the means to pay with just her salary. Our lease contract has a very clear stipulation that early termination means forfeit of the security deposit which is two months deposit. 

We were able to find new tenants and sent the previous couple notification of our intentions to keep the security deposit. They called and after many insults, they made it clear that they were expecting their security deposit back and said if they knew the deposit was on the hook they would have completed their lease.

We did find new tenants, however, while I understand they want their deposit back I've had to pay two months' worth of commissions, one for the couple that left and one for the new tenants. So in the last three months, I've to had pay two commissions. My attorney advised us to keep the deposit to cover those costs plus the cost of about a week of unpaid rent while they were moving out.

So legally we are covered, but what has everyone else done in this case?