Click on the My Notifications option under My Account section.
The Notifications Panel will be brought out. This way you can be directly informed regarding the total usage and the limits of your notifications.
For each communication channel, different limits apply. These limits are displayed on the relative Your monthly limits section.
You are also able to extend your notification limits by using Credits. The Credits you have available are shown in the relative Credits section.
Click on the Buy Credits button to get to the Buy Credits page where you can evaluate the available Credit Packs and purchase the one that suits your needs.