Going through International check-in and out procedures while having domestic flight

I flew from Sydney to Brisbane on Sunday, 05 Nov 2017 and was asked to check-in at T1 International- Sydney Airport and arrived at Brisbane International Terminal. My flight was JQ57.
I need an answer for my question why Jetstar put customers flying domestic through International flight. I was very frustrated and disappointed because of the following reasons:
- We had to come to the airport 2 hours prior instead of on-line check-in
- We had to go through all custom check-ups unnecessarily
- We had to go on a long queue together with people coming from overseas and waited for a longer period of time before I could exit the airport.
It took me almost 5 hours to fly from Sydney to Brisbane.
My e-mail address is: ngocdeane2@bigpond.com
I am looking forward from hearing from YOU as soon as possible. Thanks for your time.
A Jetstar customer



But the Jetstar web site

But the Jetstar web site booking page actually tells you quite clearly that the flight goes from the International Terminal and that the procedures are different. It details out in the drop-down box all the extra details.

I wondered why Jetstar did

I wondered why Jetstar did that to customers who flew domestic like me and others. It took us 4 hours instead of 2 hrs as other times. That would stop us to fly with Jetstar !!!! I flew with JT for so many years, but not now any more !!! It was petty.