Scammers don't care about the DNC. Only law-abiding telemarketers respect it. You might want to invest in a call blocker or at the very least, don't answer calls from numbers you don't recognize and don't call numbers back "just to find out who called." If they don't leave a message, they aren't worth your time.
This number keeps calling and hanging up. Sometimes 3-5 times a day. Go to the Do Not Call web site and file a complaint.
https://complaints.donotcall.gov/complaint/complaintcheck.aspx