Next G Mobile, a Verizon MVNO that launched about a year ago seems seems to be having some issues. For the last couple of days the Activate and Recharge pages on the Next G website have been displaying a down for maintenance message and advising customers to call Next G at 1-855-639-8455. When I called today and asked about activating I was told that Next G's systems were down and that I should try again latter.
Next G dealers have told me they aren't able to activate or top up accounts on line or by calling Next G either.
Next G recently modified their terms and conditions to include a $5 reconnect or late fee for users who lose service due to no payment. Presumably they will waive that fee for anyone who is unable to top up because of the current system issues.
I hope that Next G is able to resolve its problems. A business that can't add new customers or accept payments certainly isn't viable. There are very few Verizon MVNOs to choose from and Next G offers competitive plans that include no extra charge roaming.
Update 10 AM PST 12/11: Next G is still unable to accept payments online or over the phone. I've seen several reports of users whose service was suspended because they could not top up their accounts. Users with suspend accounts have been unable to port their numbers to another operator. If you have active Next G service, I recommend porting your number as soon as possible.
Update 12/31/2013: Next G is no longer answering their phones and the Website is down. It looks like they are out of business.