Boots.com experienced an issue where if you added two discounted Ralph Lauren gift set items to an order it applied a large discount to any subsequent items added to the order.

Boots have cancelled the orders which were made in this way...

HOWEVER...

They have honored others orders, some of which having 10 or more cameras added.

Mistakes like this are the retailers problem, not the consumers. The consumer should not be penalized with funds being held by the retailer, they should honor such mistakes.