888 Casino - Having troubles to verify my account, requesting absurd ''Notary Public'' verification

I signed up to 888casino and used their deposit bonus offers. I've deposited around £1000 in total. I never won anything from the bonus and so decided to withdraw the £1000 (I'm withdrawing less that Ive deposited). I had an email from Cassava stating they want to see documentation proof to allow me to withdraw - Not a problem. Uploaded it. But now they are saying they want the documents to be "Notary Public" verified and unwilling to accept any other form of proof. Ive found out how to get this done, but at £30 per document (Unless I am looking in the wrong places). I don't see why I should pay at least £60 to get MY money back. Its not as if I've won a jackpot or even in profit. Other Cassava sites have accepted these documents without any issues previously. I'm a UK police officer and even offered them for my sergeant to email/contact them (From his official police.uk email address) to verify who i am, but they are not interested. Any help to get this resolved would be much appreciated.