Amazon India - Cashback not received

Hello Sir/Madam,
I registered a complaint on Amazon on **st of Nov-**** regarding not receiving the cashback on * order payments I made on SWIGGY using Amazon pay platform as a payment mode and successfully using code APAY**. This code ensures that customers will get Flat Rs** cashback on the order value of above Rs *** if they make the payment through Amazon pay. Amazon customer executive promised me that they will resolve the issue in * days. The case ID number for the complaint was - **********. 
Even after ** days when they didn't provide any kind of communication on this, I called them myself, and initially after * hour of call (**mins of waiting) they disconnected the call then on the second call they rudely told me that I will not get the cashback because of weird reason and that reason is that I got the cashback on previous orders without me even applying for it, though on their terms and conditions it is mentioned that customer will get the cashback only after applying the code APAY** and that limit is ** times but since because of their system error, I was getting the cashback without even applying the code so now I will not get the cashback after applying the code. This way they are not willing to give me cashback on * orders where I make the payment using Amazon pay code in the anticipation that I will get the cashback. This way they even made me miss an opportunity of availing the cashback using some other payment channel code. 
Please tell me if the customer has not applied for any offer or cashback then how can a company impose that offer on that customer? is it a right practice to do business. How can they make transactions without proper terms and conditions? I request you to kindly intervene in these fraudulent practices operated by amazon and help me in getting my cashback which I rightfully deserve because I have used the offer correctly which is even getting displayed in the transactions section of the Amazon wallet site. Not only this when I called them after ** days of no action from their side, their customer support representatives rudely behaved with me and said "File the complaint where you want to, we will see"
All the * order id are given below-*. P**-*******-********. P**-*******-********. P**-*******-********. P**-*******-********. P**-*******-********. P**-*******-*******
I am attaching the screenshot of the oldest one.

Regards
Pallav Sharma
New Delhi-**
Phone Number - **********