Delhivery - Package not picked up

We got defective furniture (Price *****) from Amazon. On Saturday (**th December ****), Amazon placed a return request with assigning Delhivery as the courier service. Pick-up Location is within the heart of Bangalore City.
Since then, every day morning, we get a message saying 'Delivery Executive is out to pick up your order' and in the evening, we get message saying 'Pick-up request cancelled by customer'.
This is actually a very big scam & fraud -how we never get any call/msg and Delhivery (either representatives/ delivery boys) cancel order on our behalf?
We never got any calls. Delivery person never calls us back, there is no way we can reach Delhivery ! and order keeps getting cancelled without our consent and once the order is cancelled, Amazon creates new pick up and Delhivery again cancels.
Also, we tried raising query, there's no positive response. it's been * days, every day orders cancelling and they are not contacting us to pick up the furniture worth **,***. Because of all this, we are going through a lot of stress & mental harassment.
This is really important (both mentally and financially) to get this order picked up on urgent basis.
Every Day we are getting new numbers of delivery executives and no one responds to them.