Tata Motors — Tata zest have music system feature not available

Address:

Bangalore, Karnataka

I purchased my tata zest XT revetron on 16th March and that time I was assured that my music system will be upgraded for video playback and navigation system while first service, as per sales person, also same was available on tata site and same I confirmed by call centre on toll free. Now after several follow up they are telling your chassis no is old, so they will not upgrade and it's not possible. My question is: Why old chassis sold to me, without my knowledge, no discount given while purchase and now they telling available system can not be upgraded. No one bother to provide me escalation matrix and I want this to be either upgraded or replaced.