8 pin ax1200i wont fit asus x99 deluxe

Hi, ive just purchase a asus x99 deluxe and a ax1200i psu, problem i have is the 8 pin lead does not physically fit the motherboard. the series of square and rounded plastic plugs on the lead are not the same as the mobo, however the psu end of the lead also fits the mobo perfectly. it appears i need a lead with identical ends. i did contact the help desk and they kindley sent out a new lead but unfortunately it was same as the two that came with the psu. the mobo socket plug shape lines up like this-rounded,square,square,rounded the next row is square,rounded,rounded,square the corsair lead thats marked cpu lines up like this-rounded,square,rounded,rounded next row is square,rounded,rounded,rounded. does any body have any clues to this dilema, ie can i buy a third party lead with identical ends? Thanks in advance