Well there should be a "refuse FC invites" option in the game FROM THE VERY START, but since it's FFXIV and they take centuries to add basic options (nearly 4 years for allowing queues with the chocobo out takes the cake IMO), I expect this feature to be implemented in hmmmm.....8.0. Please look forward to it.

But jokes aside, the best advice is to put yourself to busy or away when you go to cities (that's where FC scavenge for people) so maybe put yourself into busy when in cities so that nobody will bother you. You won't get tells, but you won't get invites either.

Beside that, you can just ready your hand and just press refuse as soon as it pops.

Also

Quote Originally Posted by Arutan View Post
There actually is an option to auto-cancel any FC invite
Mind sharing said option that isn't the one everyone experimented?