BT WiFi How do I log out?

In the past month I think I have tried to use BT WiFi while away from home about 3 times on my ipod touch. Each time I used it for about 2 minutes just to test the service, so I reckon about 6 minutes in total. Somehow according to BT I have used over 3000 minutes. How do I log out of BT WiFi, I can't find any way to log out?

Keep the opening page open - and open a new tab/window for working in.

There is a logout on the first page after logging i.

My ipod touch logs in automatically whenever I am in range of a BT Wifi hotspot, I only saw the login page once, the first time I used a BT WiFi hotspot. I have found that you can logout by using the address https://www.btopenzone.com:8443/home