Amazon - One Plus Nord CE 2 Mobile is defective

I am Aswini. In amazon i have ordered One plus Nord CE * Phone on *th April
****. I have received the same on *th April ****. After putting my Airtel
sim (Which is already working in my existing phone) in Oneplus the set
mobile there is no signal at all and there is no *g data.I have tried to
get the signal i chose the option as *g *g then i got the signal. Then when
i choose to *g option i lost the signal. The mobile is only working on *g
and * g only. I went to Airtel showroom and i said my problem to them and
they offered a brand new sim. After putting the new sim also the same
problem persisted.
Then immediately i raised my complaint to Amazon on **th April ****.Then i
got a call from amazon team. They assured me that the technician will come
and asses the phone on **th Aprill **** at **am. As per the amazon
commitment the same technician came today at **am and he checked the mobile
and informed us the phone is defective and there is mic issue. Then the
same guy informed that the same information above the phone(Defective
product)will be updated in System and i will be getting a call from Amazon.
When i called the Customer care to know about my status then i got
information from them saying the issue was resolved.
I got a shock. And he said there is no replacement again the technician
will come verfy the phone again on **th April ****.
Again the situation is back to square one. It has been i am going through
lot of mental stress above this tedious process.
Also the Customer care agents also not answering properly and they were
rude.
I have a lot of dissopintment and mental stress for me.
I had a firm believe that Amazon Product will be good and the service will
be good.
It has been proved wrong. Please do the needful immediately.
Name - Aswini Vasu
Order no- ***-*******-*******