verizon 4g ipad mini LTE not connecting after 4-5 webpages

Purchased my iPad Mini 1 week ago with Verizon Cell Service: I called Verizon and added it to my account after a few minute download with the serial number and other id's. Next day I turned off WiFi and let Cellular take over: it told me my data usage is used up? I called Verizon and they said I have 5.8gb left and they tried to troubleshoot. It worked after rebooting the mini. Ten minutes after hanging up, the browser (Safari) hung up again? I called back and they did the same thing, sent a signal to the tablet and I had to reboot (turn off and then turn back on), first five minutes with Rep on-line it surfed just fine. I downloaded a few apps and then hung up, several minutes later it locked up again-I cleared Cache/History and rebooted and it started again? What the foohy? I called Verizon and spoke to Apple rep and she sent me back to the Verizon tech, again reboot. This *****, I hope its just the mini (this one) as I'm hoping the Apple Store has a replacement or I'm going back to a full-size version. I really wanted the mini to work but hate to have this problem in two months with the new one and get the same ole service from Apple/Verizon: "Just go ahead and Reboot the tablet" no duh it will work but it won't after 10-15 web pages? Anyone else having issues?

Also: I have two other iPads: New Gen 4 with Retina just WiFi and an older 1st Generation with Wifi and 3G (At&t). These and my iPhones have great Wifi service in my house but the Mini always shows 2 bars unless I'm over the router. Obviously the Mini is skimping on a antenna or insulation or something compared to the big boys and the iPhones? Is it me?