Cancelling a subscription in iTunes

I want to cancel my Audible subscription. I can see it in 'subscriptions' in my iTunes account and I can find 'cancel subscription' in the 'manage' section. When I click on 'cancel subscription' I see a buffering wheel and then the whole application shuts down without any opportunity to click on 'done'. I am kicked out of my account without sigining out and the subscription is not cancelled.

Help