Sony Ericsson — Servicing problem

Address:

Karnataka

Mobile WT19i bought on 17th May 2012. Within 2 weeks given for servicing for overheating and battery back up issues. When i got the mob, it was ok after servicing. Later on, battery life went down faster, network receiving problem and some keys are not working in mobile. Gave for servicing on Oct 3rd 2012 and its warranty.
Status:
Service Centre: Waiting for motherboard after informing call centre. Need to replace in the mobile.
Call centre: Blatant lies. We called atleast 5 times. Each time we called they said mobile will be ready in 5 days. Last week we called on Nov 1st or Nov 2nd, they said motherboard has been dispatched to service centre. I called up today Nov 7th service centre, they still have not received it. I called up call centre, they are not aware of mother board being dispatched last week or what is the current status. But they mentioned approval pending for motherboard to be dispatched.

This is ridiculous, when it is under warranty why this approval needed. No proper updates from either service or call centre. We have to follow up all the time.