Screwed over by ea and Xbox

Yesterday I purchased a pre order copy of the phantom edition bf6 was listed in the Xbox store at 70% off I was shocked by the price and bought immediately only to be billed at 100% I go back to the store it was now listed at 10% of after almost 2 hour conversation with Xbox support to be told yes we believe you but tuff luck it's full price 

I quess it's all about profit and screw your clients