The offers found on the Earn Gold wall are entirely run by a third party company called RadiumOne.
Please note that some offers take longer than others to credit your account.
If you encounter this problem, please send all proof of offer completion to RadiumOne Engage Customer Support in order to receive your Gold. Proof includes verification emails, confirmation texts, screenshots showing that you completed the offer, payment receipts, and charge invoices, etc... RadiumOne Engage Customer Support will need verification from you to help increase the speed in which you will receive your Gold.
You can contact them directly by emailing their support team at firstname.lastname@example.org
To contact RadiumOne Engage Customer Support, please click on the "Missing Gold?" link located at the top right of the offer wall. From there, you can report a problem for the specific offer you are having trouble with. There is no need to contact the app developer, RadiumOne Engage will work with you to credit approved Gold.