I have lost progress and now it doesn’t show up at all. And you are correct, I had that four hours of additional play (which was never credited to me) and now it is gone. Tech support is completely unhelpful.
Is this a joke? If King.com is going to promote the Royalty program and not disclose how it works (or does not), that is fraud. They take your card information as well. There have been quite a few questions about this program and no answers from King, so I have reported my experience.
Be advised that as soon as you join the royalty program: you will no longer earn credits for purchases made within the app while playing the game. AND you will have to pay sales tax.