I keep getting messages that I have exceeded my data limit, do you want to upgrade your plan? I also get "could not activate data cellular data network - you are not subscriber to a cellular data service". This is on one of my ipad minis (I have five shared devices - three iPhone 5s and two Ipad minis). It has been doing this for the past couple of months. I've been a Verizon subscriber for about six months. I've checked my data plan and I have only used about 1Gb out of my 6Gb plan and I am two/thirds through the current plan period, so I have plenty of limit left. I have done a hard reset on the mini with no help. Ironically, I even get the message when I'm connected to wifi when it shouldn't even be trying to use the cellular service. I've tried to use live chat with Verizon, but the website always says "all agents are busy". So much for customer service!!!!!! Anyone here have an idea?