I believe the only reasons you will get a restriction is leaving to many matches or bad connection. If you have only left one match then bungos systems have determined your network connection is behaving poorly enough that it is negatively impacting other players in your games and applied a restriction though I think they message you about that about assuming they have a correct and valid email and you make sure its not getting spam filtered somewhere.

Connection issues maybe? Add the 'Help' tag to see if a mentor can give you more insight as to what might've been the cause.

You provably haven't bought any silver lately. :-P