I know this question has been asked before, but they are somewhat scattered through the Scoring post, so I figured I'd post this so that everyone else with the same problem could see what exactly to do. I thought it might help to have some set guidelines.
What exactly is the protocol that we should follow when an opponent doesn't respond?
The concensus seems to be:
Continue trying to contact them through neomail, etc.
If they don't reply, you win your matchup.
Usually one player doens't respond in some groups. If this is the case, just continue trying to contact them (like thejoz said) and if the battle is not completed by the 17th, we will basically eliminate that person from the group and all scores, for and against will be void. If one person has fought all their battles but is purposely ignoring one player, then you should take screenshots and stuff...
don't worry too much about it, we will sort things out fairly for those who show that they have tried.