Does the invoice state anything about returns? I know the general Walgreens policy states no refunds for opened items (see http://www.walgreens.com/topic/help/...returns#Return), but they also have this statement on that page:

"How can I return online General Merchandise orders? If an item is an exception to our standard return policy, you will find return instructions on the receipt below the product description."

Since this is not a bottle of shampoo or OTC medicine, it might, and should, have a different policy for return if opened.