Debt collection — NAM National Arbitration and Mediation (MS)

Debt was already discharged in bankruptcy and is no longer owed. filed for Bankruptcy in XXXX. Still getting call from collection agency attempting to collect on XXXX XXXX loan. Have a XXXX form sent from XXXX XXXX for cancellation of this debt. Received a call from XXXX Service.wanting me to pay this. spoke with XXXX XXXX XXXX, phone XXXX they called XXXX. Then on XXXX received a call from XXXX XXXX with XXXX XXXX saying I was being sued for check fraud by XXXX XXXX. Explained to this person that this has been canceled in bankruptcy, also faxed the dept cancellation form from XXXX XXXX. What can I do to stop these call. Every XXXX XXXX months I get these calls. XXXX phone XXXX. Your help is appreciated.