I was sold this device under the impression that the $75 plan was unlimited, it's not. It isn't even unlimited data at all, it doesn't run slower after the alloted high speed data is used, it doesn't run at all. I paid $75 for a refill card and $50 for the device. The plan lasted one day. ONE DAY, for $75. Ridiculous, ripoff. Do not buy!!
It sounds like you were sold a device without reading or understanding the fine print of what you purchased.
You are describing the service of a Jetpack on a prepaid plan. Prepaid devices will deactivate once the data plan has been met. This is a fail safe for people wanting temporary internet access or with a strict budget. Normal Verizon devices on a data plan will start to charge you an overage fee after your plan has been exceeded. The unlimited devices will drop you in to lower prioritization with the other connected devices on your current towers.
Advising others to not buy or that all jetpacks are a rip off seems inaccurate.