You can also send a certified signature required, receipt requested letter to them that tells them to "cease and desist all communication per the Fair Debt Collection Practice Act". It must have that phrase in it. Make sure your account number and all that information on it so their can be no excuse for them not to comply. They may contact you only once more after they have received the letter to let you know what their intentions are. If they contact you past that one time after you have received notification that they got the letter, then they have opened themselves up to lawsuits and fines.