Greed gets the best of some people, including some real estate sale people.
If you can prove what you are alleging, you should report this agent and his broker who threatened you to your state licensing agency. If the actions you claim are found to be true loss of license may follow. If the parties involved are Realtors, meaning members of the local Realtor Associations, call the Association offer and discuss what steps you can take to bring a claim of ethical misconduct against both the agent and broker.
I am saddened by your experience.