How do I get ACS to stop calling me?

Fred - welcome to the forums!

You will want to send the company a cease and desist letter detailing the fact that you are not the party they are seeking, and that person no longer lives with you. The letter doesn't need to be fancy - it simply needs to state those facts, and that you are requesting that they stop calling your home immediately in their search for your former housemate. Send it certified, return receipt requested, so you know they received it, and keep that info on file in case they don't stop calling.

If they don't stop calling you after they receive the letter, you will have every right to file a complaint against them with your state's Attorney General.

Since you have registered with this site, a consultant from your area will be contacting you to discuss your personal debt situation and offer a consolidation or settlement program. If you do not require their services, please just inform them when they call.