An anonymous reader writes "On December 23, Amazon advertised a "buy one get one free" sale on DVD boxsets, but did not test the promotion before going live. When anyone placed two boxsets in their cart, the website gave a double discount — so the "grand total" shown (before order submission) was $0.00 or something very small. Despite terms stating that Amazon checks order prices before shipping, Amazon shipped the vast majority of orders. Five days later (December 28), after orders had been received and presumably opened, Amazon emailed customers advising them to return the boxsets unopened or customers' credit cards would be charged an additional amount. (You can read more threads about this here and here.) Starting yesterday, Amazon has been (re)charging credit cards, often without authorization. On Amazon's side, they didn't advertise any double discount, and the free or nearly-free boxsets must have cost them a mint. But with Amazon continually giving unadvertised discounts that seem to be errors, is "return the merchandise or be charged" the new way that price glitches will be handled?"