Battery Drain

My iphone 11 (bought less than 7 months) has severe battery performance issues. I use only apple genuine accessories (which comes along with the box). It takes long time (more than 4 to 5 hours) for a full charge and drains out in 3 hours (comes to less than 30% after a full charge). Apple support after diagnostics says that since the settings/battery/battery health shows 93%, they cannot recommend battery replacement and other support they can do. Whatever they said to increase battery life (reducing brightness, using wifi, low power mode, etc.,) all are something i do regularly. please support?