Ok, so the bonus is correctly applying, but there appears to be a display issue on iDevice. Your bonus is indeed applying correctly.
Foot I've been playing since august 2012, forts posted in forums in October so there's something wrong here.
So far, all the claims of an incorrect date that we've looked at, have actually been correct, so in that case, please email support. They'll need to verify your identity, then let you know your account creation date. If the incorrect achievement level did get applied, they can fix that up for you.