It seems like if they intended to offer the bonus to you that this is a mistake, or a company that you don't want to work for, so it should be pretty easy to ask them about it and see what happens. Any sane company wouldn't intentionally lie about this.

I mean, you can always decide to leave. So, you cannot force them to leave give you the bonus, but you could insist on it or quit. I wouldn't go 0-quitting, but you have options.

At least it's an option. Not at my current org! Been there for two years.