Royal Enfield — classic 350 sprocket

Address:

Accelerate motor (Royal Enfield) ideal homes, rajarajeshwari Nagar Bangalore-98, 560098

I had given my bike for service in R.R.Nagar Bangalore branch. Everytime they ask me to change the chain or sprocket. My bike has not even crossed 18k km. Is the quality of sprocket is Soo cheap or the service people are fooling us?
When I questioned this to a representative by name Mr. Arun in the branch I was abused by foul language. Need a resolution for this