I tried all of the above, after much frustration we paid for the up-grade fee (which for us was UK airport tax, don't get me startd on that one!!) at the airport at the Emirates service desk. If you are doing this go there firt as you can't boo in until you'v paid!! Good luck, it's a real pain. Luckily the last time i did a reward flight it took my credit card details 1st time