Heroes, skins, perks and platinum should be added directly to your client following purchase. If you do not immediately see an item you've bought, as a first step, please restart your client and check again.
Heroes will go into your usual lineup and skins will be selectable for your hero in the lobby. You can only view your perks in the game lobby, or by visiting the shop and deselecting 'hide owned'. Currency will be shown next to your username and avatar in all game menus.
If you are still unable to locate a purchase, please submit a support ticket under the category Game–> Purchases and we'll be happy to assist.