Problem is, you have to find them, and you have to sue them in their home town, not yours. You might me able to recoop your costs of the flight out there, though. Bigger problem is that most of these people are not legitimate telemarketers. They are scam artists with spoofed numbers, so it's much more difficult to track them down and sue them or get them arrested.
calls multiple times per day, every day, they've called three more times so far today - and it isn't even noon yet, each time asked to be taken off calling list and reminded them that I have been asking them to take us off their calling list for the past 90 days.
called again while I was typing this out.
looking into sending a certified "cease and desist" letter.
this is absolutely ridiculous - called again @ 3:55 PM, once again asked them to stop calling us, informed them that this was the 8th time today they've called, they said that those other calls were someone else, i informed them that they strangely are somehow calling from the same phone number as those other guys.