I have been getting called almost daily. Sometimes they call 3 - 4 times/day although they never have left a message. I've had early morning calls through late evening calls from this number. Weekends are not off limits for them either!
I never pick up the phone, I let the answering machine screen calls from numbers that I don't recognize. This doesn't deter them at all. I'm on the Federal and state "do not call me " lists too.