Note - If your purchase was a Pack (multiple items in a bundle), they are delivered to your in-game Mail you can check by selecting Mail from the Main Menu screen.
If you didn't receive an item you purchased on an Android phone, first try these steps:
1) From the main menu screen, tap on the gear icon (or your profile picture)
2) Click 'Restore Purchases' button > 'Start' button and wait for 30 seconds.
3. Check your in-game mail and the items should arrive.