Phone booked in 4 times, still not fixed

My phone switches on and off by itself.<br> I have booked it in 4 times this month for the same problem.<br> Their internal communication is worthless.<br> The phone is only 6 months old, I do not want it any more and demand a new phone!<br> I do not have a phone to use, but at the end of the month they want their money!!<br> <br> <br>