Prepaid Nano-SIM Cards? (Singapore)

Hey,

I just got an iPhone 5S here in Singapore and now have the problem that SingTel is not giving out the required nano-SIM cards as pre-paid. At least two of the shops told me they don't have them and won't cut them down.

Is there any secret tip how to circumvent the problem? Cannot imagine that all users of iPhone 5 and newer cannot use their device with a prepaid cards in Singapore.

(Actually I would only need a nano-SIM borrowed for a few minutes to activate my phone so that I can use it as non-phone)