there's a good method to make laugh of them.
-go out of the room
-create a new char
-go to the room
-kill the high lvl only using ur sword
*when the high lvl leaves the room*
-go out
-delete the char
-keep playing with ur previous char
happened to me on IGunz, i was a lv 4 and a lv 41 joined my glad room. he was like... advanced turtle and single slash strategy, so i decided to do C.O.D (Cirlcle of Death) BF and when he was at 4 HP (could record that game xD) he left the room... also, when there's a swap game (open 1v1 or even line swap), i usually go there and start killing all of them till they get out of the room so i can easily "destroy" the room (no mercy for EXP beggers >_>)