According to the the rule, they are correct. However I would agree with you that it was not a sportmanship behaviour. I recommend you to play with other players, for example me :)
(sakla) If you want to play a game with an opponent of a similar level, you can define a required BKR range for a new game invitation. Then nobody with a BKR outside this range will be able to see/accept it. (Katechka) (Bütün ipuçlarını göster)