I thought Newegg was suppose to have good customer service? You shouldn't have to pay return shipping if they sent you the wrong item, and should be able to get a refund if they don't have any of the correct item in stock. The UPC code shouldn't be a problem if it is clear it wasn't cut out to send in for a rebate, etc.
Check their return policy and see if you have grounds to argue the return shipping. If you've only been emailing one person there, see if you can contact someone else, preferably higher up the food chain, and maybe mention the Better Business Bureau. I'm not sure if there are any consumer protection laws that require a company to pay return shipping for their mistakes, but advertising one product and shipping an older version could be considered a bait and switch tactic, which is certainly illegal. Also, look into filing a dispute with your credit card company or Paypal, depending on how you paid.
DKS is available on Xbox Live (in some areas, at least) but I'm not sure what MS' policies are or if if they have a gift code system. You can email support@larian.com to check, if you can't get this resolved otherwise.
