ok thxs

That isn't something that Google would do when you think about it sensibly, rather than jump on the "I hate Google" bandwagon.

Why on earth would Google have an interstitial popup telling the user to bookmark a site instead? That means that Google would be cut out and wouldn't get paid either.
Whatever the popup was, it was initiated by the target site when the referer was from a paid ad.

ok thxs

don't forget it can take 12 to 24 hrs before click credits appear in your account.
I would (as a concerned content provider) email the Google adsense team with the details and ask them to investigate. One of the adwords policies is that the landing pages should not have popups

from https://adwords.google.com/select/guidelines.html
No Pop-ups

We do not allow links to landing pages that generate pop-ups when users enter or leave your landing page. We consider a pop-up to be any window, regardless of content, that opens in addition to the original window.