How should I deal with people who speak rudely?

Hit back just as hard.

Breathe in an annoying way, like *huff huff huff*, and smack your lips loudly during breaks, smacking your mouth shut.

That's the right way to handle it; you just can't reason with those types of people, so you should just play along vaguely and avoid them.

I'm just like, 'Oh, thanks ^^' and that's it.

Yeah, it's better not to engage them. If you try to fight back the same way, they'll either do something crazy to you or to the people around you.