With a Top-Up Card

Step 1
* Go buy a top up card.
* Prepaid top-up cards are available in $15, $25, $50 and $100 amounts

Step 2
* From virginmobile.ca select top up.
* Or dial #111 from your prepaid phone for free!
* Simply follow the instruction provided

Credit Card Top-Up

Step 1
* Register your credit card (Visa, MasterCard)
* Log in to My Account
* Pick the Payment info tab and click the add a card link

Step 2
* Top up your account
* From virginmobile.ca select top up.
* Or dial #111 from your mobile phone for free!
* Simply follow the instructions provided source

More information on topping up here