Hey So I got my 64gb Black iPhone 5 yesterday and took it to AT&T store to activate it, they upgraded my line and all was well until I realized all day when my phone was on wifi it would constantly go into a cycle every few minutes showing "No Service" then going back to full bars. Note this doesn't happen if I have wifi set to off. These are locations that I always had full bars on my iPhone 3, 4, etc. When it reads "No Service" and I place a call it immediately jumps back to full bars. I contacted Apple Support and also AT&T and tried everything they told me to do and no solution, anyone having the same problems?