I can't seem to edit my original post, so i'm going to add a few things here.

Verizon Wireless Customer Support wrote: This most often occurs when a customer is on another carrier's network and there is a delay in when the carrier bills Verizon Wireless, subsequently causing a delay in when Verizon Wireless bills customers.

It sounds like I'm being billed because Verizon's systems are slow, or because I'm using another carrier's network, and I cannot control which network I use.

Verizon Wireless Customer Support wrote: The usage and charges would still be valid.

The charges are only valid if I have gone over, and as I have said in my original post, nothing states that I have ever gone over.

Is there anything I could have done to avoid the unbilled data charge? By the time I am informed of the charge, the usage cycle is already over. During the usage cycle I'm told that I have however much data left, the cycle ends and I'm told how much I used. But then the next bill comes around and basically says "Hey, you know how we said you had plenty of data left last month, well we lied, you owe us $60". Also, the bill does not even say how much I went over, no where does anything say that I have gone over, I'm just being billed $60 with no reasonable explanation.