Dell Changed my order to prevent cashback

In March I purchased a very expensive Alienware PC from Dell through the Dell.com website. Part of what encouraged me to make the purchase was the 12% cashback being offered by Rakuten. I have always received my cashback so felt confident in my purchase. The cashback was going to be worth about $300. When I made the purchase through the Dell website after confirming the cashback was active in my browser, I received a notification that my payment through Dell Pay needed more information. I contacted Dell Pay and they confirmed a few pieces of information and then approved the purchase. I then called Dell and Dell refused to push the order through. They told me that they would create a new order for me and send it to me so I could purchase it there. I confirmed multiple times with 2 different Dell customer service reps that doing it that way would NOT affect my cashback through Rakuten.  Little did I know they processed it as an eQuote which according to Rakuten does not qualify for cashback. Fast forward to a couple of days ago I received my typical cashback from Rakuten and it was short the near $300. I contacted Rakuten and they explained that they don't pay cashback on eQuotes from Dell. I contacted Dell and they said there is nothing they can do about it. They told me to contact Rakuten. I contacted Rakuten again and they said the responsibility lies on Dell because they didn't process the transaction properly. I spoke with Dell again and they sent me to talk to Dell Pay. Dell Pay said they have no idea why Dell would send me to them and that they can't help me.  So basically, after terrible service from all involved, I am out $300 with a computer I would have never paid this much money for.  In my estimation the company responsible is Dell and all they want to do is push everything off on someone else.