did you ever notify them in writing. Haven;t checked but in many states and in many leases, all notices of termination must be in writing. If yours wasn;t consider yourself lucky they finally believed you when they did as they may have waited even longer before advertising the place.

the thing with the deposit:

your deposit can be taken for unpaid rent. as of this minute, you have about 10 or 11 months of unpaid rent. If they do not re-rent the apartment, you will owe much more than your deposit will cover.

Since the lease is for 1 year, you technically still have business with this LL for that year or until they have re-rented the unit.

I am betting that if you pay for the remainder of the year in full, they would gladly refund your security deposit.