No. The original creditor - the person you ripped off will sue you. The collection agency was hired by them to try and collect the debt, to avoid court. If the collection agency is unable to collect the debt, then they inform the creditor (the person who hired them). Your creditor will sue you. The collection agency is not in any position to sue you because they are not owed the debt. If you don't pay your debt, expect to be sued. Court costs, penalties, attorney's fees, collection fees, interest - you will end up owing a whole lot more money than what you owe now, and they do have ways to collect it from you. They won't always be nice about it.
Certified Paralegal, with 25+ years' experience.