We have three cell phones, 2 iPhones and 1 Google phone. All of our phones are connected to wifi and we are able to access the internet through wifi on the cell phones. For some reason, all of the phones are bypassing wifi and connecting to Verizon several times a day. These connections occur at regular intervals, for instance, at 12:23 am and 6:23 am. The connections use small amounts of data each time, but it is adding up to our entire 2 GB of data and costing additional money. I've called Verizon customer service and they recommended turning off wifi assist...which did not help. Another person recommended turning off cellular data entirely when we use wifi, which is inconvenient. Any advice?