Sony Ericson Mobile Under Warrant Period Not been serviced at time.

Location/place: Siliguri, WestBengal, India

Name of company/service: Sony Ericson

I had gave my sony ericson mobile at Ganapati Cellular At Siliguri,westbengal, India With The Workorder No. SE31291710484 having a warrant period.
The set is within warrant period, it was having some touch problem and got hanged up sometimes it is a new set i bought it on 14/05/2012 and it started hanging in july.I submitted it to the service centre,
They told we will change the touch pad. But whenever i call them they tell we have not received parcel and so we cant do it.
I dont know what is the main problem. Why does it take a month to get repaired? Its 16 days and i am working without a handset and i had already bought on may 14. 2012 and i submitted in jul 19.
Please Check my problem and get it repaired or provide me a new set within time from the sony ericson.
The fuul address of the service centre is ganapati Cellular, G3 Smriti Dham Building, Sevoke Road, siliguri, 734001.
Phone no. 0353-2522841.
They told me it will take 7 days .
When i call them they tell we havent received the touch pad from the company it has been parcelled. But Now also they are telling The same . I dont know when will i get back my handset.
Hope you take some steps against them and get me back my same cell r a new one replace it because it is only a 3 months set and was having many problems.