Your post is what is a bunch of hooey. You do NOT have to update your DNC registration - ever. Didn't you read the info on the site when you first registered your number?
https://www.donotcall.gov/register/reg.aspx
Legitimate telemarketers do pay attention to it. If not on the DNC list, you'd be getting even more calls.
Even calling them back will "key off another live one." Resist the curiosity and don't call back any unknown numbers. Some of them can cost you a lot in phone fees.
Called at 9 Monday morning. I must have the first call of the work week! Caller ID says SURVEY. I didn't answer—don't answer unknown callers. No message was left.