Who called from 2512029578

I find the calls on my caller ID but no message is ever left. Calls at least once  or twice a week.

I just received a call from 2512029578 at 9:53am.   I said, "Hello" twice, no response so I hung up.  I called the number back, then an automated voice answered saying, "Goodbye" but it did not disconnect.

It's a subscriber trying to get you in a fake contest

Keeps calling and it's annoying. Just a scam. I don't answer anymore. How can I block this idiot?

251-285-0210  calls daily, says nothing, if I hold the phone long enough I get a recorded female "goodbye".