Samsung India — emi interest cash back not refunded as promised

I had purchased a samsung galaxy s8+ phone on 25 july,[protected]. At the time of purchase, there was an ongoing offer:

1. Refund of emi under no cost emi option within 90 days
2. Cashback of rs. 3000 on registering the hdfc credit card on the samsung pay app and a free wireless charger by september 30, 2017.

The "terms & condition" document clearly states that the samsung pay cashback should have been credited by 30 september, 2017 and the samsung official website stated that the emi interest cashback would take no more than 90 days to be credited.

I have reached out to the helpdesk numerous times and i have not got an answer regarding when the cashback will actually be credited. All that i was told was to wait for 90 days and the amount would be credited.

I had spoken to mr. Pradeep on 1 nov who stated that i would receive a call back by 4 nov, it didn't happen. I had spoken to ms. Lizie on 4 nov, she told that she would get back to me by 10 nov, it too didn't happen. Nov 10, i spoke to mr. Bala, who assured me that he would arrange for a call back from his manager, it didn't happen as well.

Prior to all these calls, i had spoken to ms. Lizie multiple times over the last two months and she too told me the same thing which was to wait for 90 days.

Now they want me to wait for more 25 days. As a consumer, why should i wait any more even after having all the documents.

Request you to please look into this issue and help me get the refund