OnePlus India — oneplus 8 in 2011 handset

I have purchased one new on 31.08.20 from amazon. The user manual page 45 clearly depicts auto answering possible through settings. All settings were made properly but auto answering through wired/bluetooth headset failed. It was escalated to amazon technical support, who advised for return of these for issue in system. Again i purchased a new phone, but facing the same issue and escalated to amazon, who now advised to replacement and the replaced one is on the way.. I feel you have falsifying the public through false information and harassing the customers as the sellers, who have been replacing one after another.

Please resolve the issue at the earliest, else it will be escalated to higher forum for resolution with penalty