I received a Gold offer but after making a purchase I did not get the bonus gold, why?
The offers expire after a certain time. Your transferred money needs to arrive within three days after you accepted the offer in order for bonuses to be credited accordingly.
Furthermore please make sure you bought the offer on the device you received it. You will not receive the bonus gold from an offer you got on the browser if you buy from the app and vice versa.
Please contact support for additional assistance with in-game offers.