Amazon India — Phone return

Purchased a Samaung M 53 phone from Amazon on 23rd Sept. Identified a defect, it was verified by their technical team and cleared for refund. Now since over 10 days i have made requests for pick up which for some reason or other the agents are not doing, wrongly mentioning that they called and no one responded, misbehaving and not picking for no logical reason. It seems that this is a deliberate act and 5 attempts cannot be a coincidence. Its obvious that till they get the phone, there will be no refund and if no one picks in a stipulated time, it will never be picked. I have made many attempts but i feel harassed now. I spend 35 mins to 1 hour in explaining my case to each of the new people in call centre. They just give promises but on field the agents play dirty.