It happend in china, it can happne in singapore too. why
not.
phones that are traded in, sold to second hand shops,
stolen.....etc. It can go back to manufactureres.
So the manufacturers give away those old phones to staff? i dont
think so.
They can keep the parts inside, well, perhaps need to do some
cleaning. And then give it a brand new casing, brand new key pads,
put in a brand new box. Give it a serial number as if it's a brand
new phone.
Then it will be supplied to the shops.
p.s. For that particular customer, if she got the very same phone
from singtel, but the memory of any sms/pics/contacts are all
erased, she wont be able to tell if it is a used phone. Box is new,
casing dont have a single slight scratch, memory emptied. all types
of serial number are matched. How can you tell? So those who
thought they are holding a brand new phone, can they be 100%
sure?