robo calling from 213-257-5233

The spammers are not really calling from that number. They "spoof" the number that shows on your Caller ID.  If you call that number 213-257-.....  the recording says "this number is disconnected or changed".   It is a Verizon wireless number that is not in service. 

You can buy a service called Selective Call Rejection from Cox for apx $5 a month.  It lets you block 29 numbers.

You can buy a Call Blocker. Consumer Reports just did an article about the 5 most popular ones. None of them is perfect. 

The number you mentioned offers a "free cruise" but of course you won't really get a free cruise. On one spam-fighting website alone there were 58 pages of complaints about the number that called you. You are not alone. 

One person said that you should hit the # key on your phone 6-7 times after you answer the call. That tells the spammer that your number is not in service. I just started trying this and can't verify that it works.

You can buy one of the Panasonic phones that let you block 250 numbers ( i don't work for Panasonic).  It works well. But the spammers keep changing the number on the Caller ID so you are going to block 100 in the first 2 months. 

Being able to block 30 numbers is almost as useless as the DNC List. Other phone carriers are able to block numbers but Cox has chosen to make us pay to block just 30 numbers. It's time to find a carrier with the ability to respond to it's customers' needs, not their shareholders'.