You don't have to renew your DNC, once on it it is there until you remove it. They changed that way back. By "renewing" it all you do is open yourself up for legal telemarketing calls on top of the scams for another day's.
Do consider maybe getting a call blocking device or phone.. You can google them and many are around $60.00 or so.
Report your callers here, not just to the DNC alone:
https://www.ftccomplaintassistant.gov/#&panel1-1
https://esupport.fcc.gov/ccmsforms/form1088.action
https://complaints.donotcall.gov/complaint/complaintcheck.aspx?panel=2
By State DNC lists:
http://800notes.com/res/DoNotCall.aspx
FCC Abandoned Calls Complaint form:
http://www.fcc.gov/cgb/consumerfacts/1088D-R.pdf
email:
[email protected]