AirAsia are a basta*d to deal with like that.
That 'payment pending' bit happened to me too, again AirAsia.
Itinerary change is also useless on line, plus they really charge for it, might as well just buy another ticket,....on another airline.
Once you've clicked the go buttons there's no go back to rectify any mistakes.
Their blurb says that you can contact this or that address to change things, but it;s a minefield trying to sort it with them.
“Is it not written in your Law, ‘I said, you are gods’? John 10:34.