Unfortunately, iTunes can occasionally encounter a processing error when purchasing webcasts on our app.
After completing your order and receiving a confirmation email you should see the pre-ordered webcast under My Webcasts.
If not, your order did not complete successfully.
Get a screengrab of your empty STASH/My Webcasts page and send that to iTunes support. You should not have any problem getting a refund for this purchase due to a processing error at the time of purchase.
If you order directly on our website we can help you with any billing issues ourselves.