Hello Govern12,
Are you sure you reviewed the correct plugin?
The tawk.to messaging plugin is completely free to use, there are no fees at all.
The only thing we charge for is Live Answering (hired agents) services, and for custom Add-ons like Video Chat.
There are over 650,000 users on tawk.to, all enjoying a 100% free service.
Let us know if we can help with anything else?