Sony Ericsson — No stip providing

My mobile is sony ericsson W20. 3 Years before its purchased. Now sony is not develop any spare parts for it. My mobile is damaged and service centre told me to change stip.. Due to unavialbility of the stip I can't repair my mobile. When we purchase a cell we expect that will get a good service from company. But after some times all companies close their exisitng product and going to new launch. So normal people will be compelled to buy a new cell. My word against company. I need justice from you.