I received a letter from a company name United Debt Solutions,LLC. Saying failure to comply may result in recommendation that further action be filed against me in my county. This account was closed back in Sept. 2001 and what I owed back then was $1171 now they are asking for $13,802. Can they still take me to court after 6 years.:

Depends on where you live, what the debt was for, and when the last payment was made to them. It is very possible they can't, but without enough info it is just a guess

Respond in writing by disputing the allged debt, demand that they validicate the alleged debt. Demand they producethe original contract.