Royal Enfield — knock sound of engine

I have purchased a classic 350 redich red bike from pinnacle thrissur just before 4 month. Almost 7 or 8 times iam taken to the service center inspite they cannot solve my problem and iam not satisfied by the use royal enfield and also iam spend more of my times for this. I need a fair action from your i expecting good return from your side
Hope fully jithin

(Chassis no. Me3u3s5c1hk514047 vehicle no. Kl-46-r-2161)