Lenovo — Merchant cashback not received

I have purchased lenovo ideapad S-340 from Lenovo exclusive store( Systech IT Solution Pvt. Ltd.), using ICICI Bank credit card under no cost emi and 10% cashback discount which was told by the store manager. I haven't received merchant cashback of Rs 2595 yet still after passing more than 75 days which is even mentioned in the bill.

Even after repeatedly calling customer care, store manager and mailing to lenovo customer care i am not getting any response into that