So I went to see the the mac people again today, this guy is even more agressive, keeps telling me it's the apps that are killing the battery but wouldn't point out which app(s). Then tells me to turn off notifications, location, background datas etc...
FOr the record I only have 4 apps (WhatsApp, games, wallet app)...showed them the celluar data usage and it's right now only 110mb...guy kept on telling me to do this and that to save battery.
I am talking 5 ish hours of usage compare to 1.5 days.
All the people who I spoke to that has iphone 5/S said on regular use, their battery would last upto 1.5 days...which aligns with my previous experience with iphone 3G and 4...
very sad for Apple
My 2 cents to those who's having issue with their unit and after 1 visit to the Apple store and issue is not resolved, don't wast your time and money - return for a full refund asap before the grace periot runs out.