Sorry to hear that :( very easily done.
A new remote and cut key will cost £214.01 inc vat plus the cost of programming.
Andy
Ah, sorry,did not realise you had lost both keys :(
As your dealer has said, it will require 2 new keys, a key ID ECU and a Certification ECU and the dashboard needs to come out to do the job.
The best thing you can do would be to get your dealer to order a new key blade, which is about £30 iirc and then you can unlock the car then if you still cant find the old key it would be worth checking if your car or house insurance covers you for lost keys.
Andy