My phone just started shutting down especially when I was on the internet like FB. I did some research and saw that it was most likely a swollen battery issue. Before I could get the new battery the phone got stuck into airplane mode. Got the new battery a few hours later and replaced it. Couldn't get the phone to reboot. Finally had to do a factory reset. Now I am getting a message that I am low on storage. My phone has 16GB. Shows total space 11.5 GB / available space 9.39GB. How do I get this message to stop?