Maruti Suzuki India — missing of chip after service

Sir,
I took my brezza car for first service to fortune cars, bhiwadi, rajasthan and after that my navigation system didn't work which i noticed after 2-3 days of service. Then in 2nd service i told them about this problem and after service they told me that a chip is missing from my car. That's why my navigation doesn't working then when i received a call from their office about the feedback of the service. I told the lady who was on phone that my chip went missing after first service, she told me that u should have complaint us after 1st service. I told her that i didn't know that there is a chip in my car. After that she told me that she would call me regarding this, till now i didn't receive any call. My phone no. Is [protected]. Please resolve this issue at the earliest.