Amazon India — promotion code cs10 discount 10%

Address:

Hyderabad, Hyderabad, Telangana, 500079

I ordered a mobile paid rupees 12300. Promotion code cs10 applied for discount of 10%. 1200 discount credited to my account. Again i ordered another phone during offer period without discount becoz the discount is applicable at one time only.
The first ordered phone was delivered and i found it is a defective product so that i requested replacement but no stock so refund intiated. Refund was intiated only for 11100 saying 1200 discount was not available.
I called customer care about issue they said cancelled orders are not eligible to get discount so we detected discount amount and refunded remaining amount. I requested to apply offer to second order. But refused saying only one time offer can be available.
I said in this regard there is no cancellation request or no fault from my side. Defective order delivered, replacement request also not fulfilled and refunded less amount by amazon completely amazon fault and i lost 1200.
Becoz of the offer only i ordered items otherwise i could not ordered. There is no single fault from my side all mistakes by amazon and so i requested to apply offer to second order which placed during offer period.
But no proper response.

As i am a business customer of amazon i know what are the actions they take if we not follow the policies, but here amazon it self they are not following policies.

As a business customer of amazon, i know that amazon is customer friendly, but in this case they are not following ethics.