Performant Recovery Inc formerly known as Diversified Collection Services Inc Performant Recovery trying to collect on a 11 year old La. tax debt Pleasanaton California

I received a letter from Performant Recovey trying to collect a debt for the La. Department of revenue. The State of La tried telling me after 11 years I didn't file taxes for 2002 and I owe $5,600 in taxes. First of all I thought under the fair credit act this debt is to old to report to the credit reporting agencies and there is no way I owe this. I am 48 years old and have filed taxes every year since I was 15. In 2002 I worked part time and attended school so i only earned $30,000 and was married and had two kids that I claimed all so how could I owe $5,600. They likely would owe me, plus we filled taxes every year. next i tried calling the La. dept of revenue and this is like dealing with a bunch of ignorant monkeys. No one helped and just kept directing me to website or #'s that I just kept getting shuffled around. I spent days dealing with this and got no where so now I'm getting turned over to a second party collection agency. I did some searching and cannot find where PRI has a license to collect debt in TX and this is well over 7 years, so where is the fair credit act on this?

Also, they are very arrogant and believe i owe this dept so where do get help for this?