Are you click on the buy gold option and nothing happens? If so, this article will explain how to fix it!
If your purchases aren't going through completely, then Steam has a very good knowledge base article about this here.
Additionally, make sure you that are accepting the charge through the Steam interface. Multiple confirmations are required when adding funds through Steam Wallet to then make a subsequent purchase.
If you made a purchase through our website or the steps above don't help, please create a ticket here and we'll get you fixed up!