I did retail tech support in my company for 2 years, and also this entailed a lot of customer service/dealing with customers. Bottom line, the customer is always right.
I'd ship it back, tell them it's defective, they'll have no choice but to accept it.. Trust me, ppl did this all the time with us and we had no choice, you can't decline a return.
Here's the deal, assuming the case isn't sealed with warranty stickers, open it up, pull thedata cable halfway off the burner or similar device, and return it for an exchange. (If it does have a warranty sticker, use a hairdryer to heat it up and slowly peel it off, it works
) They'll be forced to refund you the difference and you can get the same, discounted unit plus your money. If they bench test it first to verify the error, (which they never do because of the logistics nightmare)they will get an error from the device with the loose cable.
Basically, they will much rather save the sale by selling you a cheaper unit then lose the sale altogether. That way you can get exactly what you want;)