What a cheek to change my flight time without consultation!

I changed a booking with Kulula by extending it for a few days and paid almost the dame amount as my original ticket. Then Kulula decides, without consulting me, to change the time of my new departure time to an hour earlier in a Sunday and just sends me a confirmation email, not even flagging the fact that they have changed my flight time. I demand to be put back on my original 9am flight! What a cheek. They get to make changes without consulting the client but when I make a change I have to pay a fortune.