In the second case i.e. if you are subscribed to the Blackberry/Smartphone plan, you can continue browsing on other sites which your plan allows you to access.
Alternatively, you can top-up your credit using a recharge card or login in here to recharge via etop-up to continue enjoying seamless access.
Please note that you may need to opt in to a data plan to enjoy a discounted billing(i.e. NOT at pay as you go rate). You can verify that you are on a data plan by using the SIM STK menu or by dialing *228# Users with existing Quickteller ID and password can log on with same credentials