The DNC does help by keeping you from receiving calls by legitimate telemarketers. However, it doesn't cover calls from charities, surveys, and other non-telemarketers. And scammers certainly don't follow it. If you can, block and ignore their calls.
Called a trump phone aka obama phone I missed the call over two hours ago [***] my name to those do not.call list
These calls go to any cell phone it's annoying