Thanks, I didn't notice another option but granted I was rushing! I think it's probably too late now
edit: just saw that page again, and noticed the two seperate options. I thought I needed to tick both so selected the first (correct) one then the next one which switched it to the wrong option. Oh well
edit2: actually the more I think about it. Why on earth would they lock you into a payment option before getting to the payment screen?!