that's because at this time, Australia isn't on the E visa system. Once they switch over, you will be booking return flights or the system rejects the application if you can't fill the required fields in
I have a feeling, either somebody who is English or someone who has a good command of English and can write it, put the Hull requirements together and made it simple to understand.
There is, or at least was a sign up in that office regarding going back with your updated bank book, 90 days after receiving your extension. I wouldn't totally rely on getting or not a piece of paper. Jomtien Immigration, do like too throw a curveball on occasions.
It's a simple date mistake. Read the stamp 'Extension of stay is NOT approved'. You need to get the date corrected. If you stay beyond the 7 days, you'll be on overstay. You need to leave before 23.59pm the 17th November.
A date stamp is your responsibility to check it is correct and if not, get it corrected