Who called from 5057976321

This number calls without leaving a message.  Calling back does no good.

Citibank-Citicorp Credit Services Inc
Albuquerque, NM 87109
(505) 797-6321

I was harassed fifteen times from this number, I explained about ten times that whomever they are trying to reach doesn't have this number, and the fact that I don't have an account with them, and could they please stop calling, I ask to speak to a manager to prevent them from calling and they said they don't have managers, and called again  about twenty minutes later.

you would think, if you didn't answer the phone the first 5 times they called they would stop calling

is there any way to get them to stop calling, they must've called me over 100 times since november i do not answer my phone, and don't even listen to my voice mail, you would think they would get the hint if you don't answere your phone