Bajaj Auto — Pulsar DTS-I break down related

Address:

A/24 Shrihari banglows-1, near chamunda temple, zadeswar road , bharuch, Zadeswar Baruch, 392011

I bought pulsar 150 DTS-I bike in mid of 2018.
Today I went for start bike and it did not start.
So I want to know the reason that the bike is still four years old then why it is not running smoothly. And i faced this problem has occurred twice in four years.
I want to know why this problem occurs even though the bike is serviced on time
Please give me solution ASAP.