It's a nice thought, but nothing would happen. They might even just cancel the chat to annoy you. Or they might continue asking you questions. In either case they wouldn't owe you money for it. They didn't engage into a contract with you just because you sent them that message.

That said you might have certain consumer protections you're not aware of. I had cell phone plan with Comviq here in Sweden that I wanted to cancel and they said on their website that I needed to call. Swedish law requires my being able to cancel in various ways (e.g. sending a letter, or sending an email, etc.) regardless of what they said in their initial contract. So I found an address and just sent them an email stating I wanted to cancel. In a day or two it was done. I presume they know they are legally required to do so and so they did what I said, but I'm also sure they happy to provide conflicting information making consumers unaware of their rights. I reported their website to our consumer protection authorities, but I never heard back.