Srilankan Airlines — missing my bag 16th jan ul 208

My name is supratim dey. I travelled from abu dhabi to colombo on16 th jan 2018 at 23:00. Economy class ;seat 33a;ul 208;etkt[protected];
And colombo to kolkata on 17th jan 2018 at 08:25 ;economy class ; ul 187;etkt[protected]. But i couldnot get my one luggage & complained to the authority, but i couldnot get any response, plz take action against it & help me to return my belongings.