Battery drain

Recently got my new iPhone 13 Pro 128GB

set up and right after I notice de battery drain….. when to bed the next they/morning iPhone was dead, I plug it in when to my settings-battery settings- notice that cellular data 48% but my cellular setting ( network ) was off, I was using my iPhone on wifi only. Locations setting are off, somehow cellular date is killing my battery 🔋 without using cellar network/data

please help

currently on IOS 15.6.1 not willing to update to IOS 16