While buying a mobile mobikwik having offer now unable to access

Mobikwik is offering Rs 200 cashback on adding Rs 200 to your mobikwik wallet, this offer valid only for Nokia Lumia 640 only and valid for 5 times each month 1 times for 5 months, how to get.?, just follow the steps below:- The code MOBILUMIA can be used once a month for 5 months with a max. of Rs. 200 cashback every month. its showing every month we can add

First month i got 200 cashback on adding of 200 …Now mobikwik telling the offer is expired i complained also they are not responding properly i have mobikwik complaint ticket no.3364024 . And i requested to call back for my number but no response very worst response because of competing to others they are fooling people. Kindly help me to get solution for this

Thank you in advance.