Is an escrow argeement void if the buyers fail to hold up their part of the agreement in whole? Can we get legal fees if we sue? Cost is $2500

We sold a house in NYC that had a violation remedied by a GC prior to the closing. The Dept. of Buildings needed to inspect and certify the completion of the work. We entered into an escrow agreement of $10000 to be held until the job was certified. The new owners have not allowed entry into the house, even though the GC and inspector made several appointments with them. The last time the inspector was at the house he issued a violation because he witnessed an addition being added to the house without a permit. Then the part that we removed due to the violation that we had, was reinstalled. (Which was a basement bathroom.) Many structural changes have been made, so our remedied violation can no longer be proven. Their lawyer refuses to have our lawyer release the funds to us because is clients have issues not related to the violations and never communicated what the issues were. The agreement was for 60 days and extend another 60 over a year ago.