I apply for a 12 month statement a BBL for my extension, 200 baht collection in 7 days.
I then get a mini statement on the day of application, done in branch while I wait to cover the 3 weeks or so between the end of the 12 month statement and day of application, along with updated book and letter from BBL confirming it's my account.
Been doing the same for more than 15 years.