Royal Enfield — Engine turned off and tappet sound for 7months old new bullet

Address:

Chennai

I bought classic 350 bs6 model 7months ago. Am facing tappet sound in engine and while riding vehicle gets turned off.
Now they are saying one of the parts in engine need to be replaced so that will not get these two issues in future.
My concern is to refund or replace with a new bike. But they are not rewdy for that instead they saying only parts can be replaced it seems