Forget my previous post, I've found my diamonds in the zen-diamonds trade window. There's a "claim" button to get the right amount of diamonds for the char and possibly leave the rest for some alts.
No astral diamonds for me as well after purchasing the €55.99 founders pack. Got everything else (just had to relog after purchase) from both the courier and the founder vendor (some items in the mail and the starter goodies bag from the vendor) No astral diamonds tho. Should I open a ticket in game or this post is enough?