Brand new iPhone 11 battery draining overnight while it in use

I’ve had my iPhone for 10 days. From day one the battery drains within just a few hours. I’ve tried every fix I can find online. I have everything from Bluetooth to Siri turned off but it isn’t helping. I’m also running in dark mode and put it in airplane mode to try to preserve battery. I have to charge my phone twice a day. Before I go to bed I charge it to 100%. By 7am after no use it’s drained to 43%. It always says Siri has used 70% to 64% of battery BUT SIRI IS NOT ON. I’m very frustrated that I have a brand new $700 phone that I can’t even use the functions on.