Etihad Airways complaint: Website online booking.

Guest number 500031609534.
Today (22222) i am trying to book flights from Manchester (UK) to Sydney on 26th Dec 2022, returning Melbourne to Manchester on Jan 16th 2023, BUISNESS CLASS. The website gives the following flight available: Man-Syd via Brussells, flight numbers SN 2184, EY58, EY454.
Mel-Man EY463, EY15.Total Price £8704.94
I then tried to book these flights using my TRAVEL BANK account balance and the outstanding with my credit card. It allows me to proceed, putting in passenger details, select seats and then asks how much of my balance i would like to use (entire balance), takes my credit card details and then when i press the purchase button it states that this fare is not available.
I have refreshed this many times, used different domains but each time the same result. I phoned Ethiad via the phone number given and they state that this is a website problem, that this flight option is not on their booking systems and that they cannot help me!!
I have a saved screen shot of this flight and its price, i would like someone to please book these flights for me at the price your website states. It appears that there is no one from Ethiad willing to help me as they keep stating that this is a website problem and there is no one to assist.
I have a large amount of money in my TRAVEL BANK ACCOUNT, if you are unable to supply me with the flights above (or similar) at the cost the website states then please can you refund me my money from my TRAVEL BANK ACCOUNT.
Thanks.
Kevin Hughes.