Ask a Business Lawyer. Get Business Law Questions Answered ASAP.
A deposit is a payment required by a landlord from a tenant to cover the expenses of any repairs of damages to the premises greater than normal "wear and tear."
The security deposit must be returned within a short time (varying by states) after the tenant vacates, less the cost of repairing any unusual damage. Unfortunately for tenants, these damages are usually subject to the judgment of the landlord, who may desire to paint and refinish on the tenant's money, which results in many small claims suits. In a few states the security deposit must be kept in a separate bank account, and some states require payment of interest on the amount held as a deposit.
A security deposit is sometimes confused with a deposit of the "last month's rent," which may be credited to the tenant for the final month's rent. A security deposit cannot be used legally as a rent credit.
The landlord has no right to keep your deposit if there are no repairs to be made. You just need to sue him in small claims court (sue in the county where the rental space is located) to recover your money.
You're right that this is a totally separate issue. His marketing for you has nothing to do with your rent or owing him money on the other matter.
You need to sue him as soon as possible to get your money back.