Sony Ericsson ( W200i) / Non Replacement of Cell/Delay in Repairing

Dear sir,

I am Samir Patel from Baroda,India .I have bought Sony Ericsson `w200i Cell phone before 3 months and within 2 and half months there was camera problem in it and the service engineer admited that its company fault ,despite of the company`s manufacturing fault they failed to repair or return the cell after 15th day today also and dont want to replace for a new one also.whenver i ask for my cell they just say your cell is still with head office and yet to come.

Do u know the exact returning policy ?
Do u know the legal rules in India abt non replacement of cell ?
How can i claim for my cell as after spending money we have to wait for the defect product and we are helpless after buying product from these companies.

Samir Patel
Baroda.