You don’t. If they don’t wanna be here, don’t take on this huge crusade to get them here. You can lead a horse to water, but you can’t make them drink. They must take the final step themselves.
Focus on making lemme a desirable place to be, less on getting people to use the communication tool you happen to prefer.
Report it to the BBB, not a bunch of internet randoms. Anti-trust laws don’t work if you only report crimes online for updoots.