I assume you mean £2000. I transfer £1500 each month and the charge is £15. You can check the Wise rates without logging in. The exchange rate is good too. This month Western Union were cheaper by 200 baht but you can't gaurantee ftt. Swift transfers gave me an awful exchange rate as I suspect your bank does too.
Check with your office. Mine required banked money 3 months prior to application and it is of no use trying to argue with what they say even if they are wrong.
There is a high possibility you are being scammed for every penny they can get out of you. I might be wrong and hope I am but if I was you I would proceed on that basis.