I am on social security disability and I am 61 years old.a finace company has threatened me with lawsuit.I have been told that social security cannot be garnisheed.and if I let them know that it is social secutity disability they cannot freeze my account.is this true?

Yes it is true. You need to let the company AND your bank know that your money is from Social Security.
It can be garnished IF it is a student loan, back taxes, child support or anything to do with the government.

If they file lawsuit, you can file an exemption of property. You can list your bank accounts. I did that and I did not even have to send proof. I just stated that all money in the bank account were from SSDI and the court ruled in my favor and the company could not go after it. But, I am learning now, from people here, that they can file a lien against your home. That is happening to me. I contacted the agency and they put me on hardship payments of $15.00 a month and they even froze the interest. Contact them and see if they will work with you in the fashion. Good luck.