How does the Auto Top-up for 1511EXPRESS service works?

ZONE Telecom > Consumer > 1511EXPRESS
Once your account balance reaches $5, we will top up your account by the amount you have selected at registration. The top-up amount will be charged to the credit card, which you registered during sign-up. 
We have three Value Plans under 1511EXPRESS service: Saver Plan ($18), Standard Plan ($38) and Premium Plan ($68).
There is also a top-up bonus credit of 5% of the value plan selected. The top-up amount, bonus credit and the existing balance will have an expiry period of 180 days from the latest top-up date.
We will notify you of your top-up either through email or SMS to the designated mobile phone number.
You can also choose not to be notified of any auto top-up to your account.
You will be given the option to select the preferred mode of notification at the time of registration.