Havells India — Poor response

I hav opted for an AMC plan for water purifier in the may, service dealer said your existing filters are gud now so complaint next time to change filters, later I booked slot for servicing, I asked for filter he said we will hav to check either I m saying correct or not. Since then I have requested 5 times to the service dealer to check the data and change my RO's filters, he is delaying it for more than 20 days by saying "Sir I m telling u in an hour". Since then I m getting this statement every day on my whatsapp.
Am I paying thousands for this ?
Or should I warn everyone in family relatives n frnds not to go for havells in the future.
This is too much, for how long should I beg for what I have paid.

Serial no. 67HCG60100283
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Registered in the name of:
VINOD KUMAR PANDEY