Credit card debt was turned over to law firm. They purchased it from a collection agency. I am living off for social security. According to the letter have 30 days to dispute the validity of the debt.

Letter also states that "at this time, no attorney has personally reviewed my account.

What shall I do?

It matters to know when the debt occurred. How long has it been. Credit card debt is purchased many times; oft times it is not a law firm that has it, but another collection agency with one lawyer on staff.

So, how long has it been ?

How old is the debt and is it a real law firm or just a debt collection company that use one attorney for about 20,000 debts to threaten people with.

First I would always claim the debt is not mine and ask for proof of debt. They may not be able to provide any proof. And also if they don't provide it, that gives you other rights.

Yes, that's true, often when the debt has been sold many times over (for so many cents on the dollar) the proof of debt is long gone and the new collectiion agency have only minimal information to go on.

I am thinking that if the debt is old enough, the statute of limitation may have run out, making this a moot point.