if you unlock it it wont help with service, unlocking it means you can just use it with other carriers such a t-mobile,do you have a case on your phone? try taking it off i had a case that use to kill my reception, if the problem still continues, try using google voice or textfree which allow you to use wifi to make calls and texts ( don't worry its free you just get a free number from the application but also get to keep the att number)