Anne Wong Holloway's problem with "unintentional purchase" at Apple's Appt Store has been resolved -- soon after she wrote to them and hours after I had posted her story on this blog.
Lavanya of iTunes Store Customer Support wrote to Anne to say that she would be "more than happy" to fix the issue.
She promised that "in three to five business days, a credit of 43.97 USD should be posted to the credit card that appears on the receipt for that purchase."
According to her, the iTunes Store provides a warning message that asks if you are sure that you want to buy an item. This warning can be turned off. If you would like to make sure that this warning is on, you can reset the warnings in the iTunes Store by following the instructions in this article:
Resetting iTunes Store warnings
This is indeed helpful to its customers because Anne says that when
she posted her problem in a Discussions group, she found from the response that there was a significant number of people "bitten" by the App Store bug.