Now lost a few games because of players 'flagging' then playing on - really sporting. I'll not be accepting anymore 'flags'

I am guessing you are saying people are saying "gg" before the game is over? If you are then they aren't saying they're conceding at all.

No I think he means when people say ohh let me flag, and then don't actually flag and play for snookers and win the game, I never let people flag unless I know they are not coming back from it.