Ashish Verma

Hi,I bought Samsung Galaxy Ace 1 week earlier and i m having problem wid it already.WHEN I switch phone on packet data signal/sign is present for few minutes and i can connect to internet but after few minutes (5 min.) signal disappears and i cannot connect to internet.In the mean time phone also says that no SD CARD detected AND NO Network available .I showed it to samsung service center and they formatted phone and updated it to new software version but still i am having same problem .First,i thought their might b problem in my sim but when i insert into my another mobile phone(NOKIA) it works FINE.Plz Help me on this issue as soon as possible........