If this was a normal commercial lease, then rent would be payable in advance (generally 3 monthly) throughout the term. If you are saying that you paid rent in March 2009 & had always paid every 3 months up to then, then your rent was actually paid up to June 2009. If you correctly terminated the lease in March (i.e. let the landlord know and he accepted it) then you should get the payment you made in March back. But why did you pay it? Did you not know you were paying in advance all the time? Check the lease to make sure that was the requirement.
So far as the deposit is concerned, there should have been a checkout done (jointly by you and the landlord)when you left. The landlord would then have been able to say whether any repairs etc. which you were responsible for under the lease had to be done. If none, then the deposit should be returned. If no checkout was done & you do not have photographic evidence of the condition you left the property in, you may well have a problem if the landlord claims you left it in a state where he had to spend the deposit money on things you should have done. It will be your word against his.
Ultimately, if you can't get satisfaction you will have to take him to the small claims Court.