Staples I place an order at 7:30 pm tonight after going to staples.com and seeing a banner that says 50. Off 200. If I use visa checkout. I did and did not get the 50.00  Internet

I place an order at 7:30 pm tonight after going to staples.com and seeing a banner that says 50. Off 200. If I use visa checkout.  I did and did not get the 50.  I called staples and was transferred to visa (staples said it is visa and not them). I was then transferred to capital one and then 3 more agents before back to visa who said staples is responsible.    I have spent more than 2 hours on the phone so far and no one seems to be able to help with this obviously False advertising.