MY uncle got a spam text message from SingTel Mobile number +441548312048 asking him to key in his personal contact details within 1 hour to win a Samsung phone for $2.50. He submitted his personal details and he got suspicious when the website asked for his credit card details next. He asked for my opinion and I found that the mobile number is from England and the website isn’t related to SingTel at all. My uncle was nearly cheated because he trusted that SingTel has such reward system. 
I hope everyone is aware of these scam messages and hope that seniors would not fall for it.