Lenovo — phone broken by service center

Address:

New Delhi, Delhi, 110052

I gave phone to service center for repair under warranty they kep the phone for 3 month and whej i went to collect it, it was broken, when i asked about the crack they said it was already broken, but it was't and now they r ready to repair it or replace it. When i said to repair they srartef fighting i said to call manager but he was not available i have attached the service slip pls help