I had problems with my phone draining my battery too fast so I decided to call up this T- Mobile store for some advice. I talked to a helpful rep on the phone I think his name was Gil who offered to change out my Sim card for free. He thought that may be the problem because my card was so old. I went over there and got the new sim card and he transferred all of my contacts into the new one. It was up and working again and now I 'm happy to say my battery is no longer draining fast!