If you're playing on multiple devices, please note that items do not sync across devices and will only show up on the device you claimed or purchased them on.
If you're only playing on on device, and are still having trouble, please submit a support ticket in the game, by tapping the "gear" icon on the map screen, and then "support," or you can open an online support ticket here.
Please be sure to include the number of each type of item you had before they went missing (coins, boosters, etc.). If you don't remember the exact number, give us your best guess and we'd be happy to assist you!