Motorola Mobility — Service not proper of service center

Address:

Pune, Maharashtra, 412206

I buy Moto g4 on 12 Sep 2016, its having problem to screen then i submit the phone to Kavya Enterprises Pune. they change the screen of phone. few days back phone having battery problem so i go to Service Center on Karve Road they said there is no any history shown for this phone & there are some screw missing and some are changed in this phone we are not going to accept this go to the Service center where you repair this phone the i go to Kavya Enterprises again now they are saying we will check if we found anything physically i am still waiting for there reply and there number is showing off. if I change my phones screen before then how its not record in history. Phones warranty is still on. PLEASE HELP HOW CAN I REPAIR MY MOBILE NOW.