Amazon India — failed to deliver on time and not accepting return

Address:

Hyderabad, Telangana, 500018

Iam a amazon prime customer and ordered samsung mobile on 21st october 2019 and it was supposed to delivery by 22nd october 2019 by 9pm. But it delivered on 26 october 2019. So they failed to deliver on time due to that i cant full fill my wish. So i have called customer care and asked them to allow me to return the mobile but they refused to do that because as per policy mobiles only can be replaced and not to return. I understand that but what if amazon fails to delivery on time and what is the point of taking prime membership. Customer care agent also talking rude and he said he cant help and he is not even ready to take complaint and he said "do you what ever you want" and we are not going to help you on this case.
To avoid this situation i was trying to cancel the product but in app/website it did not allow me to do and it says its already in transit you only can cancel once it delivered to you. But once it delivered again it is saying you cannot return as per the policy. I want to understand here who is fake is problem with your website or with your customer care or with your policies.

I do not want waste my hard earned money of 7000 rs just because of amazon fault.