Yes I had a similar thing happen to me with Telstra many years back however they did manage to give me a credit. I guess you could write an official complaint to Optus or speak to the TIO if you feel strongly about it. Information on how to this can be found on the link below.
I used to work in sales way back in the day. As far as forward dating port in requests are concerned, it was always tricky and there was a specific process that needed to be followed. When we input an order, we're prompted to enter your port in details (that's the losing carriers account number and matching DOB).
We'd need to input mock details then submit the order. We'd then need to go in and submit the port on the requested date of activation.
Alternatively, we'd save the order at point where we're prompted to enter the port details. We'd then submit the order on the activation date.
You're more than welcome to send us a PM with your account details → http://yesopt.us/pmdan, I need your full name, DOB and account number. I should be able to apply an adjustment to offset any fees incurred by the loosing provider. Look forward to hearing back 🙂