When you make a purchase, the repayment will commence on the second payday cut-off following your purchase date. 

E.g. If your payday is every 15th and 30th of the month and you placed a purchase on the 14th of January, the repayment will commence on January 30. 

1st payday cut-off from the time of purchase: January 15

2nd payday cut-off from the time of purchase: January 30 (start of repayment)