We called them back tonight. A recording says "Automated OptOut Service for (323) 281-1272. Optout service is required for FCC." Then it says it will ask you to confirm the number calling you & the number dialed. It gave the correct calling number, but we didn't confirm anything - we just hung up & added them to our BLOCK list.
THIS IS A SCAM AND A LIE.
The law does NOT require YOU to opt-out of telemarketing; you are opted-out by default (so to speak). Telemarketing is ILLEGAL unless there is a pre-existing relationship w/in a specified period of time. Companies you are ALREADY affiliated with (like credit cards), are required to allow you to opt out, & you opt out with each company directly - not some generic caller claiming to be following the law whilst breaking it.
I suspect they use this scam for multiple numbers to either cover their bums OR data mine.