Currently when you try to join a clan, the confirmation screen tells you that you have already applied and do you want to cancel this application. It leads people to think that their application is a duplicate and they then delete. I get repeated applications and withdrawals that are seconds apart, sometimes 4 or 5 times from the same person. It is very confusing for the new players and could easily be fixed.
Perhaps change it to "You have successfully applied to the clan..." instead of already applied to a clan. And switch it to a yes / no option so non-English speakers don't think they have to click the only button offered to them.