If there are enough evidence that the vendor's lawyer collected the balance sum and did not notify the vendor, 
never reply the vendor. They also created a few false documents to let the vendor think that they are corresponding with purchaser's lawyer.
When the vendor demanded the lawyer with threats to report to Council BAR and the police if they don't pay, the lawyer agreed to meet in his office but during the morning of the meeting day, the vendor received a strange e-mail with a message "WARNING , you are in danger, do not go to your lawyer's office".

Please advise. Anyone have such experience ?