Ok, then from a purely legal perspective, there is no law that would prevent them from turning the account over to a collection agency. There is no type of legal "stay" that occurs when one party files a lawsuit to prevent the other party from trying to collect.
However the debt collector is governed by the Fair Debt Collection Practices Act and you can notify them not to contact you unless they "validate the debt" by providing information from the original creditor stating answers to the following questions:
What the money you say I owe is for;
Explain and show me how you calculated what you say I owe;
Provide me with copies of any papers that show I agreed to pay what you say I owe;
Provide a verification or copy of any judgment if applicable;
Identify the original creditor;
Prove the Statute of Limitations has not expired on this account
Show me that you are licensed to collect in my state
Provide me with your license numbers and Registered Agent
If they don't provide that information to you, then they have to stop contacting you under the FDCPA or you can sue them for $1,000 per contact after that.