Home buyer threatened our lives,and,Agent calling security on us

Worst experience ever, we sold our house in Sagewood Estate ,Cape town,with the help of the Only Realty Agent who also stays in Sagewood Estate,,who is also our neighbor,its been 5months,now and we have bot received the full balance,when we follow up with the buyer,he sent my husband's number to a **** who called and threaten my husband,that if we don't back down the buyer Tom, is going to send his Chinese Mafia to deal with my husband,We now fear for our lives,we didn't know that selling our home would bring us such grieve