From their policies page:
For wrong items, missing items, shipping damage or other discrepancy customer should report to RMA Department on the day in which the items were received. Any claims after business day of receipt will not be honored. Customer is responsible for keeping original shipping box for inspection. Failure to maintain original box, will void claim and replacement. NO EXCEPTIONS!
If it goes through, and when it arrives it's not the 6800U, better contact them THAT DAY if you want to return.