Unfortunately this is the way of the world. People do quit when playing after a bad shot, or a bad score but determining if it was because of a disconnect or if the player exited out of the window is impossible. Punishing all who did not finish a round would not be fair to those who genuinely were disconnected, or a life situation took priority.
I do agree that joining a country club is a good way to avoid people that quit during a game due to a bad shot/score and if someone is disconnected during that round, you have a good idea that it was either due to a connection issue or something came up that took priority.
If you were playing a credit match or Skins/Blitz game, contact CS and let them know what happened to see if you can be refunded the credits for the incomplete game. Its not ideal, as I am sure most players would have liked to finish the round but at least you may not be out the credits.
All the Best,
WGTShamWow