I just purchased a prepaid Pocket WiFI Pro Starter Plus yesterday.
It should be a mobile modem with 94 days' 6 GB data (Online $89 after 10% discount).
right after activation, My Vodafone webpage told me it is 3GB data within 30 days.
There are two different starter packs for the Pocket WiFi Pro modem, so it sounds like your order has been processed as the $79 3GB for 30 days started pack, rather than the $99 6GB for 3 months pack.
So that I can find out why this has happened and get it fixed for you, I'll need to get some more specific information from you, so I've sent you a private message with my contact details. You can get to your private messages by clicking here.
Once I've received your email, I can take a look at your original order and see why it has been put through as the $79 started pack for you. From there, I can ensure that this is sorted out as quickly as possible.
In the meantime, please let me know if you have any other questions or if there is anything else that I can help you with.