I booked an economy class flight during the double SC offer that I’d like to change to business class to get extra SCs. Does anyone know will I get double credits on the full business class award rate if I do pay to change it?

Does anyone know when booking via one of the discount websites (Expedia etc) if you can see what class fare you're getting? I want to get the double SC offer on an economy flight to London, but prices for the dates I want to travel have jumped right up on the Qantas website.I can see the same fli...