Bajaj Auto — bike shut down during running

Address:

Ajmer, Rajasthan, 305001

I purchase bajaj discover 150f and after that its shutdown when running.. Its not run more than 15 to 20km regular and shutdown... I checked with anjita bajaj ajmer more than 5 times.. They said cdi required change.. I change cdi as well as change air filter oil filter chocks but after that no solution and same problem persist till time.. Now service centre executive unable to find out what is the problem.. If a service centre executive not know about problem then how a small mechanic is know about it.. Please suggest for same..