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Timtammi
In my opinion, first priority is sorting out flights. It sounds like there has been a schedule change, or the booking was made incorrectly. Either way the airline needs to make good. They need to confirm you on alternative flight.
Once your flights are confirmed, then ask for assistance in form of lounge access. It is a bit of a long shot IMHO, but you could point out that you had specially chosen an early evening flight. I am not sure you will get far as the airline's obligation is to get you from A to B rather than at a set time.