Problem with My Account

Hi,
I have a problem need to be solve, I need your help. Urgent!!!
I have purchased Garena Shells in https://gold.razer.com/ using Razer Gold Wallet.
After purchasing the item, it did not appear in my account. They did have given me a transaction of the purchased item. It shows that they gave me the pin code and serial no. But I do not know how to use it. Please tell me how to use the code. Tq