I bought a Verizon MiFi 2200 and when I was talking to a version salesman in the store he assured me I would have signal at my house and it would work. He promised me if it did not work and I did not use very much internet and I returned the mifi within 30 days I would not be charged anything, even the restocking fee. Well I took it home, plugged the mifi into my laptop and it started to download the software and within 1 minute my laptop smoked (I mean smoke came out of it). I don’t know if it had anything to do with the mifi or not. So I hooked it up to one of my desktops and took me 3 days to get it to connect (after I talked to Verizon via the telephone, they told me a tower was 4 miles from my house and I should have no problems connecting to it. They also said the tower was to the west of me) So I went and got a 25 foot USB extension cable and put the mifi in a western window and finally got it to connect and I activated it. I then disconnected the usb and hooked it up to my desktop wireless and tried to open msn.com and after 1 minute half the page appeared, I moved it around the house and tried with no luck. I have the device on for about 5, 10 minutes max and decided it was not going to work. So I took it back to the Verizon store where I bought it and returned it with no problems (I did not have to pay the restocking fee). As part of the return I talked to Verizon on the phone to cancel the service and the agent on the phone said it was all good. The salesman even said we were good so I assumed we were good. Until today I get a past due notice for $235.00 from Verizon (which I only bought the mifi the 5 of dec 2010 which isn’t even 30 days as of yet, so how is my first bill past due?) so I get on the phone and after about 20 minutes they took off the $175.00 early termination fee and said I used 2mb of service so I owe them $60.00. That is **bleep**. Only having the mifi hooked up for no longer then 10 minutes and not being able to open up even 1 full page how did I use 2mb of service. Anyway I had problems with Verizon about 5 years ago and left them for AT&T and have been happy. I was stupid thinking version changed they are a very bad company to deal with and the mifi is a piece of junk.
This sounds unusual even for Verizon.
There is still options for you though.
Contact Customer Service again and ask for a supervisor.... explain the billing situation, in a (forced) calm voice, and ask for a credit to your billing. I was able to work with Verizon on many billing issues and have been able to resolve them to my satisfaction. (billed for text messaging on a data modem several years ago)
Let us know how things work out.