Caller rings and hangs up as I dont answer. I create a fake contact in my phone and then send the call straight to voicemail.

Calls and hangs up when you answer.

Correction:
The caller has a lot of numbers at his disposal.  He can call you from any list of telephone numbers.  This is a scam artist.

This caller gas a number of telephone numbers at his disposal.  He will continue to harass you.

They call several times a day and disconnect as soon as I answer