nothing happens to your rating unless no moves have been played, 1 move has been played or 2 moves have been played by each and white plays the 3rd while black doesn't resigns.
anything else ur rating shud go up unless it's a bug
edit: assuming u played a rated game
I recently played someone on live chess and they resigned, but I don't think my rating went up. Does your rating go up only when you mate them or just not every time you win?