If the collection agency lied to you, there may be a violation of the FDCPA. If they are trying to collection debt that does not seem valid or more than is owed, there may be a violation of the FDCPA. You may be able to sue them for violations and be compensated. You should reach out to a consumer protection attorney. Most of us will do a free evaluation of your situation, and can likely resolve your case at no out of pocket cost to yourself.
This answer is offered as a public service for general information only, does not create an attorney-client relationship, and may not be relied upon as legal advice.