Hello Tanaka,
I would recommend checking this sticky thread and following all the steps:
This error can be a bit difficult to diagnose via forum, since it can be caused by many different reasons and some of them are related to hardware. That’s why it’s important that you try all the steps.
About the penalties, I’m afraid we can’t modify how the system works. The system can’t really discern reliably if you’re getting disconnected because of a technical issue, or leaving the game on purpose. So, to avoid abusing, the system treats everyone that leaves a match in the same way. You can read a message from Jeff Kaplan about this here; it’s more about disconnections, but the same philosophy applies.
Got feedback about the support I’m providing? Leave your comments here!