WTH... send to singtel service centre n they say they need to send it to apple for evaluation for 3-5 days then can tell me if I can get a replacement set...
normally when we send phone down, they will do a 1-1 immediately right?
It usually means that they are reluctant to change a new set because they don't know why your iPhone has this issue but at the same time acknowledged that your set is still under warranty and will only change if Apple have checked and agreed for it to change.
What you could have done is to call Apple on the spot and speak to the CSO over the phone telling him/her that 3-5 days wait is unaccepted because it leaves you uncontactable and you need to have a phone due to business needs, etc etc.. There is nothing bad or evil in this case because you need the phone and Singtel only listens to Apple. So you bridge the gap by bring Apple directly to Singtel instead of waiting for 3-5 transportational days.
Apple will usually negotiate with Singtel back room staffs to change one on the spot for you if the phone is really deemed spoilt.