Stovekraft Limited - Heavy noise kitchen chimney not meeting db level

I purchased kitchen chimney, model black pearl **cm, which should be noise level below **db, but it is very noisy db level arround *** db.
I purchased on ** may, and very next day I reported that concern by mail, after that they only reply as we will send some person but physically no one come to rectify this issue..
Dealer also said this matter company will solve I can't do any thing.