I'm looking for some help with my 6s. It's been activated for a while, but recently it tends to drop service consistently. I've gotten a few sim card error notifications, but it doesn't happen every time. There is another iPhone 6s in the household that doesn't drop service. I tried to order a new sim-card just to check that, but the link for ordering on the main site appears to be for people looking to transfer a new phone over to the network, not existing customers.