Apple iphone poor servicing by Cms info

Hi, my iphone 3gs mobile got damaged and have vibration and network issue.I went to cms info,hitech city branch,they took my mobile and committed to rectify all those problems.After 3 days they gave my mobile and I found all the problems were as it is. Then they said they cannot rectify this problem and committed to refund my money and my mobile in the same condition whic it was.After that when I came there I found that they took original parts from my mobile and still that mobile is not working.I took 2 days leave from my office to take my mobile and it cost around 4000 rs. Note: they always give false commitments to the customers,they donot recheck the mobile as well,and even they donot give original warranty cards of the parts which they replaced.So customer will never knows that they get original parts in their mobile or not. Please take necessary action againt him.