Who called from 2135772222

Just got a call from the number with a recorded message telling me that I should not hang up, etc. I've been getting bombarded with similar robocalls in the past few days from various numbers.

The call is a recording of an advertising for an alarm system. i am on the do not call list.

just godt one too, to my att cell #....wonder what the source of the list is, or is it random generation ?

They called last night and I chose the option that I don't need an alarm and they are still calling

the above phone number or similar '213' phone numbers call my cell phone almost daily.
Is there a sulution to blocking or stopping this harassment?
Please advice.