Security Deposit

[tenants]

My husband and I moved out of our apartment two months before our lease was over because the tenants above us were incredibly noisy at all hours of the day. We lived with that for 3 months, and we were very polite and tried to do anything we could to make the situation okay. We gave the landlords a month and a half for notice, and they said that as long as the place was rented for the 2 months that we weren't there that we could have our security deposit back... It is now more than 3 months later and we don't have our deposit back. We left the apartment in much better shape than we found it in, and the noisy neighbors moved into our apartment the day after we left. The landlord gave them a discounted rent which meant that the landlord lost $100 a month for the two months we weren't there. The landlord has decided now that that money and another $100 should be taken out of our deposit for no particular reason. This means they are willing to pay us back $1,800 of our $2,100 deposit. The question is is there anyway to get the other $300 back from them? If we accept a check for $1,800 do we loose our right to the other $300 if we were to go to small claims court???