I just spent £664 on upgrades for my pc from pcs. My pc currently has 2x2gb samsung 1333mhz ram sticks. I decided to get 8gb more so i got 2x4gb ram sticks from the upgrade your pc menu. I presumed it would be the right ones but its 1600mhz! Ive gone into the upgrade my pc again and there is no option to get 1333mhz sticks. Im guessing 1333 and 1600 cant go together so how do i change to get the right ones? The payment has gone through but it has not been dispatched.