As soon as you know these are sleezy crooks, just hang up and block the number. What with be criminals, they don't care about the national DNC, and they don't keep a record of your request. Engaging scammers is a no-win most of the time if all you want is your privacy.
I made the mistake of letting them quote on new A/C system for which they thought they could get partial payment by gov't/utility. As promised, they had scheduler call within a few minutes, and appt set for next day. I waited all day and nobody showed or called. Now, they may call multiple times per day. I suspect when I block this number they'll just switch to a different number. I'm guessing that the callers actually work for a 3rd party canvassing company, not ClearView -- that's why a scheduler from ClearView had to call me back.