[Resolved]  Sony Ericsson / Cell Phone W380i — Defected Phone since the purchase

I have purchased Sony Ericsson W380i phone on August 15, 2008, when i insert sim card in the phone after reaching at home it was showing Network Error i checked with sales man he said that " Sir this is network problem check with your network provider" when i checked with my network provider they told me there is no fault in our network for cross checking you can insert other network providers sim in your cell. I check with another sim card and the problem was same.
Than i again went to the shop from where i purchased this cell phone than they said sir now it seven days completed we cant change this phone you have to send it for repairing. I sent that for repairing and repair center found its phone fault and they changed the some part of the cell phone and given me back. Network was OK but i couldnt use that phone due to bad experience in the begining. So i continue with my old phone and kept it aside. after 4-6 months i again start to use that phone and this time with the slighghtly network problem there was some problem in its flap screen. I again send it to repair and after getting repaired i again started to use that but after two days it started to show the same problem once again. I am still having the same problem and its going to complete One year of purchasing this phone, but i couldnt get the satiscation of new phone as sony is known for providing for their products. Please advice me how can i get proper satisfaction from my phone. I am really fed up with this phone.