Put in another way, your first 25k makes u ES and that is now history. That is why your elite miles were reset. You now have to earn another 50k to hit EG. There is another way, by invitation. If SIA identify you as a potential frequent flyer, they may upgrade u before you accumulate 50k. Usually a few would be that lucky as with my frd, with 36k and receive a complimentary upgrade to EG.