Badabing writes
Bloody hell. In Hong Kong, you just stick your card in a special
machine, insert money, and your card gets credited and off you go. I
was under the impression the Oyster would be like that.

It is. You can reload your Oyster at 'special machines' at tube
stations - (otherwise known as the bog-stanhdard touchscreen ticket
machines).

Renew 4 days in advance???? WTF???

Over the web, or by phone.

A quick glance at www.oystercard.com would have made it all clear.

--
Dave