Keeps calling me and leaving blank voicemails. My voicemail notifies callers I am on the Do Not Call list, and that they will be reported.

Update: I called this number to tell them that if their company continues to call me they will be sued for calling my number that is registered on the do not call list. Company seems to either be a telemarketing place, or a collection agent. The guy said he took my number off the call list, hopefully the daily calls from this and the related numbers will stop.