return for exchange

I went in to buy a digital camera went for one that I had before as it gave me no hassles at all found out when I got it home it was faulty so took it back and was given a sony instead don't know what wrong with this thing its expensive and when taking photos of images half of the images come out very dark and you cant see them as a result I spend a lot of time redoing the images to go onto face book also it states in the book that it should charge when connected to the computer it doesn't , I want this one returned an one of the first ones I wanted sourced ( I think they had another model of this camera that I returned I am quite happy to take that one as I think this sony not very good for taking close up pictures of images