Royal Enfield — chain sprocket damage so early

Address:

Indore, Madhya Pradesh, 452018

I have ridden my classic 350 only 7300 km till now i have been maintaining my bike according to companies norms and servicing it regularly from last 1 year and 4 minths but the last time i serviced my bike i complained about the tuling noise coming from chain the service people told me that we need to change the chain as it is damaged but no rough terrain was rodden by me or no rash driving i used to do i asled him that how can it got damaged with in 8000 kms he said that just rode for 4000 kms more and change it he just lubbed the chain and told me to rode for 4000 more and change the chain and sporkit both also he told me that sporket is fine but we have full kit of chain and sporkit so you have to change both. Please resolve my problem my contact number is [protected] i am from indore madhya pradesh