@Jenli *******
they did NOT apply at Chaengwattana, and at their office the 30 day under consideration stamp is ADDED to their current expiration date, that's why when they applied on July 2nd (a MONTH before their extension ran out) they got an U/C stamp until Sept 1st
Sadly, their info has NOTHING to do with you applying at Chaengwattana.
As I said you can do when you have 45 days or less left on your current stamp)
AND
you will get a 21 day under consideration stamp and have to show up on that day.