I have an LG G4. My phone died completely, so I put it on charging and it started charging. I left it like that overnight but when I woke up it was dead. I opened the back cover and found that the battery was bloated. I went to buy a new battery. For testing purposes, I put the new battery in. The phone turned on fine but the battery percentage dropped every 5-10 seconds. I took the battery out and thought that the battery was faulty. I took it to another shop who also put a battery in but it did not turn on. I tried others, but the phone just doesn't turn on, although the batteries are charged. What should I do?