Cell given for servicing but still not returned!!!!!!

Location/place: Kolkata

Name of company/service: Nokia Care

Given my Handset-Nokia C6 to Nokia Care-Infotel Services,1, Ekdalia Road, Kol-19 on 7th of June’2012 and the target delivery date in invoice of the same was 7th June’2012. But as of now it has not yet been delivered. They keep on delaying the delivery date on enquiry!!!
Jobsheet No. : 265504886/120607/68.

PLEASE HELP ON THE SAME!!!