Nokia India — nokia 5 not returned by the service centre

Address:

629001

I bought a new nokia 5 on 29 march 2018 from sri ram mobiles, court rd, vettunimadam, nagercoil, tamil nadu 629001.
The phone started to malfunction from the start itself, however i updated the software through wi-fi and continued to use it with minor glitches.
Then i sent it to service centre (Apn plaza, opposite hindu college road, chettikulam junction nagercoil tamil nadu 629001) on 02 may 2018 for fixing software issues.
Imei no of the phone is - [protected]

It has been 1 month today and phone not returned yet. The service centre personnel are not answering my phone call. Upon visiting the service centre they say that the 'mother board' has to be replaced and has not arrived yet.

Poor service and poor customer grievance readdressal.

Awaiting prompt response!