I can't get any sense from them either - and they seem ready to
disclose passwords and registration details as long as you have your
Oyster card number at hand.

Since registering with Oyster over two years ago, I have never been
able to log on to the website to top up or check usage etc. I have
called the helpdesk numerous times (perhaps the input O2 and 02
perhaps? Misspelt my password?)

"No, we have your email address as xxxxxx and your password is xxxxxxx"

(Still didn't work).