I had someone I found on craigslist fix my iphone3G when it broke and when I turned it on after it was just like before. (I did have a backup on iTunes just in case)
what kind of issue are you speaking about, maybe a little more information will help us help you
I am sorry to hear that ,I think you should take it to the shop and check what is something wrong with your phone .And if still keep the warranty ,you can maintain it in shop where you bought it.