Why is my iPhone charging backwards from 20% to 1%?
So my iPhone 6s had a dead battery and wouldn’t turn on even if u charge it so I decided to go to a local mall to fix it and when they fixed it, it was at 39% and then I started to realize the battery kept going down really fast and when I finally got home it was around 20% something percent and it kept charging backwards dropping and dropping now it is 1% I’m not sure what to do. Should I go back to my local mall and waste money to get it fixed again? I don’t know what’s wrong with my phone?? Please help.