I was in Singapore on 3rd of September 2016 and bought a prepaid SIM card from M1 outlet at Changi Airport (T2) I followed the instructions and carefully selected 5 days plan service, however this service was terminated after 9 hours of used.

I called the customer services and answer by one lady with strong Singapore accent. She told me that the credit was used up and need to be top up but I explained to her that I selected 5 days services why end up so early she then reply that was what the system shows!! and guess what she hang up the phone straight away, I actually didn't aware and still keep explaining to her. What the 'First' services in the world. When I wrote in the feedback and again no reply from them.

My advise is keep far away from M1 when you come to select internet or carriage provider. M1 will not delivery as what they promised.