Hello I have an Iphone 4, which I love, however these are my problems. I can't phone people - 40-90% of phone calls depending on things. I can't receive calls - 60-90% of the phone calls don't get through. Of the phone calls I can get through or received I end up having 50-60% of these calls which very bad interference and nobody can here me due to it being so loud, in fact its so loud I can here it through the phone call. I created this thread, http://forums.macrumors.com/showthread.php?t=969716&highlight= I have signal, no idea why but its got a lot worse. I am with o2. If they are not providing me with a reliable network, would I be able to get out of the contract. I have had 4 sim's that are not working correctly - had 3 sim swaps. I had problems on my 3G, but nothing like this on the 4.