My new unlocked iPhone 4s keeps displaying No Service. I just bought it two days ago and from day one it has often been displaying "No Service" in the upper left hand corner. This has happened at least 10 times where it automatically loses connections. First it would automatically have service again after a few minutes but now it has taken much longer to reconnect service. It also automatically connects to AT&T but I am using a T-Mobile sim card. I don't know if the problem has to do with the sim card because I had to cut it from my iPhone 3 to fit this new iPhone 4S. It looks like a small part of the sim card's gold plate was cut off. I also updated to the newest software for the iPhone 4S. This No Service problem has never happened with my iPhone 3. The internet connection in my house has had no problems. I also have the issue when I am out of the house. I can't make or receive calls when I have no service and this is a big problem for me. I would appreciate any help. Thank you!