There may be occasions when the connection between your game and the server might be interrupted for a micro-second and your winnings, prizes for completing Stamp sets or Missions do not appear to be added.
Before anything, first try restarting the application. Usually, after turning the game off and on again and making a fresh connection to the server, your prizes will appear.
 
If you have tried restarting the game and your rewards are not added, contact our Support team with as much information as possible - including any screenshots which may assist them in locating your account and relevant game sessions.
They will be happy to attend to your concerns.