Amazon India - Product not received but status is delivered

i placed oneplus ** phone order on Amazon India on **st May'** and the delivery was on **nd May'** for this transaction i took my friends help for payment and later i would pay and also selected exchange offer on my current Oneplus * phone, **nd morning i get a call informing product will be delivered by then i had formatted my current phone using factory reset option, the delivery upon coming informs me to install Amazon app on the formatted phone which took time and he waited only for not more than * mins and he left the place in this time he didn't even check my current phone on its status but i get an email stating phone screen is damage and along with body and the exchange offer price drops from ***** rs to **** rs seeing this i was shocked on how pathetic it can be , while the delivery guy left he mentioned since its taking time product will be delivered tomorrow ( i assumed/convinced myself stating issues was from me and kept and waited for next day morning, delivery guys calls me and drops by secures OTP from me for delivery and completes the transaction and confirms product delivered on app and email and messages and get all these notifications , upon me asking about exchange of the phone only then he realises this product is on exchange policy he calls his supervisor who was very rude with me and he instructed the delivery guy not to give the product and take it back with him and later in the evening the delivery status will change (so far as i am writing this mail the status of order is Product Delivered) i tried reaching our on call for * to * times everytime i had to explain everyone on the issues since all the calls line was getting disconnected and they didnt call back even. and on chat services the comprehension skill was so bad they hardly understood about my concern almost * to * agents come online and kept transferring me to one to another which was so stressful and agitating. i have place cancellation request so far the status is not showing as order cancelled still it is showing as product delivered, looks like big scam is happening and Amazon is part of this scam since they are not taking any ownership here. need help in addressing this issue.