Hindustan Unilever Limited / Pureit Compact — demanding extra money for replacement of kit

Address:

West Bengal

I have a pure-it compact ,when I have replaced my first battery kit ,i called your pure-it help line no and they send me your representative ,named Sameer Rajak at my residence. From pureit help line it had been told to give Rs 380/- for the replacement of the same but Mr. Rajak,Malda Division of W.B refused to take the amount rather urged me to give Rs 400/- for the same. That time I kept silent but second time I directly called Mr.Rajak to change the same battery kit but this time he charged Rs.410/- instead of Rs.380/-.This time he repeatedly threatening me if I not paid his demanded amount he will neither visit nor provide any kind of service regarding pure-it in future.He also threatening me if I register a complain through pure-it helpline no, he will not visit my residence. Under this circumstances how can I get services for any pure-it complication and also take necessary steps so that people like Mr. Rajak will never been able to give such threat or not take extra money from your customer.I have a valid cash-memo for the above said amount which is signed by Mr.Rajak .
thanks with regards

Debnath Dutta