WebStore, What should I do if I receive "Well, this is embarrassing...when trying to make a WebStore purchase.

WebStore purchase with Credit Card does not complete properly

This error (see full text below) can occur when your WebStore purchase with Credit Card does not complete properly. This typically happens during times of heavy traffic in the shop.  The exact cause is not clear at this time but WebStore is working to find the cause and remedy it.

As suggested in the message, please contact us, webstore@illinois.edu so we can examine the situation. You may find that there is a transaction on your card account. We can determine if this is a captured transaction or if it is just an authorization. Once we examine your purchase attempt we can make a recommendation about what to do next.
Full error text:
"Well, this is embarrassing...
 An error may have occurred and your request may not have been completed. If you were trying to make a purchase please click on the back button and check your Order History before trying your purchase again. Do not hit submit a second time. We apologize for the inconvenience.