Each loan has a loan schedule which tracks when your minimum monthly repayments are due.
Regardless of whether you have chosen to pay weekly, fortnightly or monthly, the due date is always month after the loan is established (we refer to this as the 'anniversary date').
If you chose to pay weekly, your repayments will start a week after the loan is set up to ensure that you have made 4 payments to the loan by the anniversary date.
Your Minimum Monthly Payment is $400 and you chose to pay weekly.
You would pay 4 installments of $100 per week starting 1 week after the loan is established.