Here's why you're getting calls from 608-371-6666 (NOMO):
To ensure that we don't block important calls made by humans, when a suspected robocaller calls you, we answer the call and play the following message to them: Click HERE
If the caller successfully enters the random number (technically called a CAPTCHA), we send the call back to you but we change the Caller id to 608-371-6666 (NOMO). If we didn't do this, the call would get caught in an endless loop.
Here's an example. Let's say that Shady Charity, Inc is making some calls to ask for donations. Their phone number is 800-555-0100 and, of course, it's blacklisted. When they call, they'll hear the message asking them to type in a random number but, since they have live people making the calls, they're able to get through.
You'll first get a call from 800-555-0100 and then it will stop after one ring (because we answered it). After a slight delay (while the worker types the random number) you'll get another call (it'll be the same Shady Charity worker) but this time, the Caller ID will show as 608-371-6666.