I got my iphone5 6 months ago. Even since, I have had to do factory reset 4 times. Once in a while my iphone does not work and I cannot make a call or send a message. However the internet through wifi works. At first I thought there was a problem with my service provider. So I did a test by replacing my sim-card with the one from my wife. We both have iphone5 and have the same service provider. Her iphone5 works just fine. So when I put her sim-card on my iphone, it still did not work. But when I put my sim-card on her iphone, it worked. So I concluded that the problem was with my iphone. And each time I did a back-up and factory reset, after which my iphone5 came back to life. I am tired of doing this every month. So I am here to get a permanent help. Is it normal that my iphone5 stops working every once a month? Is it a known issue? Is there a permanent fix? Thank you in advance for your help.