Received my iphone 6 promptly but hasn't worked ...

Received my iphone 6 promptly but hasn't worked properly since I got it . Touch screen acts up and is unresponsive at times . Have had to go back to my old phone as new one was too unreliable and am sending new one back (apparently at my own cost!) to get fixed. Will update when I get it back . So far I am not happy at all with my purchase and wouldn't recommend at this point.