学生证只适合一年内短期交换生在到期前最后4个月离境并1年内不再回来
Eligibility criteria:
If you are on a student pass, in addition to the above criteria, you are eligible only if you intend to depart and remain outside Singapore for a minimum period of 12 months. The Scheme also only covers goods that you purchase in the last 4 months to the expiry of your student pass. The goods must also be brought out within 2 months from the date of purchase.
http://www.customs.gov.sg/leftNav/trav/Tourist+Refund+Scheme.htm
下面是法律责任(possible坐牢)
Making a false declaration in the refund form to Singapore Customs is a serious offence.
Taking the goods out of the Departure Hall or passing the goods to someone else after getting the refund form has been endorsed by Singapore Customs is also a serious offence.
Offences committed under the Scheme attract penalties and possible imprisonment.