In warranty phone not repaired for more than 20 days

Location/place: Mumbai

Name of company/service: Micromax

Name: Rajesh Shah (Phone 9833722542)
Model Number:A75
Jobsheet – SALMH026R485 (given at Andheri West Numbai)
Problem: No Network shown on phone
In warranty phone not repaired for more than 20 days. They say that spare part not available.
Phone bought just 3 months back.
No response/help from Micromax helpline and email id of [email protected]