Eureka Forbes — Filter kit issue

I was promised 25% discount on filter kit on buying 699 AMC, but technician came home but didnt replace filters stating that in his eureka forbes app on phone such discount isnt visible. I had wrote so many mails to company and their grievance officers but they are not resolving my issue. I have proof of this offer on mail and on call recordings, but still company not resolving issue. Intially i asked for single filter that was damaged but my request wasnt addressed hence had to helplessly go for 699 amc that was offered along with 25% off on filter kit. Please resolve my issue and compensate me for the time and stress that their team has given me since 4th feb by neglecting and ignoring a customer requests.