You've asked for a way to view your purchases, and now you can! Head to your Personal profile on the web, the click the 'Reports' section. On the left, choose the 'Purchase History' report, and voila! You're now able to see a history of your purchases for each studio you visit, whether the purchase was a cash, credit card, or 'other' purchase (check, free, etc).
You can also Export this file into a .csv report for easy editing, viewing or to provide to your employer!
See the screenshot below for an example of your new Purchase History!