Hi Sir. Yes R100 should buy you 5 credits - with which you can buy a total of 5 files anytime there is a need. Credits orders are processed immediately and by the system so there is no waiting time after the order. You can buy 5 credits by logging in to your saroms account > and then navigating to My account > click Buy credits - and proceed to checkout from there.
And this here http://help.saroms.co.za/index.php?qa=1341&qa_1=how-does-the-new-credit-system-works
is how to use the credits once you have them allocated to your account.