My iPhone 5 is increasingly giving me 'No Service' from my network. It is clearly not a problem with the network itself becauase when I restart the phone, I immediately get a fullish 3G signal. However, if I don't restart it, the phone, will sit at 'No Service' for hours meaning that I miss calls and texts. I have had quite a few replacement iPhone 5s from Apple because of bad batteries, and most of them have been like this to a certain extent. This one is the worst of the bunch, though. Are there any ways around this?