From SingTel:
Allow us to share that the customers have to meet the following requirements in order to have the iPhone exchanged.
1. Must be a SingTel set.
2. Must be within warranty.
3. SIM tray IMEI must tally with the unit’s IMEI
4. Phone must be powered on and/or can be detected in iTunes.
5. No signs of liquid damage/contact on the unit.
6. There are no signs of tampering.
7. No cosmetic/physical damage on the unit.
If the iPhone is out of warranty or found with liquid damage, or cosmetic/physical damage, it is chargeable at $350!!
Other discussion:
https://www.facebook.com/singtel/posts/10152148590481677