> If they do like it, what's the issue?

Are you serious? However goofy that sounds, they paid for a specific fantasy. They would not have paid if you advertised the service as "talk dirty with a random dude in India". If the reason they paid for this service is that they were promised a specific person, that's fraud. As simple as that.

Your judgment about whether the services are equivalent doesn't matter. If I pay you for Gucci socks, and you intentionally send me cheaper HZBZZYXY socks from Amazon instead, that's fraud even if they're still socks.