New iPhone 13 battery drains ~20% within 24 hours while completely idle

My new iPhone 13 which is undergone around 8 complete charging cycles has a serious issue of rapid battery drainage. As soon as I noticed that, I have done some tests while keeping my phone idling. for 24 hours the battery has been drained for around 20% while keeping phone absolutely idling (No Sim, No Wi-Fi, No Bluetooth, No Background Apps running). Only 3 minutes of screen on time for entire 24 hour period and a single bar at that time duration is shown under usage section of the battery. The issue is much worst when using. When contacting Abans PLC (Apple Authorized Reseller and Service Provider) and Apple Singapore who is related, informed that the diagnostics test has been passed and no response was provided. I am extremely sure that this device is not capable of holding the charge. I have sent the details to Abans PLC with screenshot evidences but they have just ignored that. I believe that with this device, I have just wasted my money as no any responsible person is providing a feedback.

I know how these systems work but any responsible person related just ignore everything. Can anyone confirm what can I do with this defective device? To whom do I complain such issues of ignorance, Apple USA? Is there any specific email related in customer complaints? This request is raised in this community before moving to the local consumer protection authority. Thank you

[Edited by Moderator]

Original Title: Brand New iPhone Battery Drains ~20% within 24 Hours When Completely Idling- No Sim, No Wifi, No Bluetooth Connections, No background Activities