Iphone 6

I have tried to factory restore my iphone around 20 times and i always have the same error, i try to restore the iphone by using the itunes method but this doesnt seem to work, i am now stuck with a black screen telling me to connect my charger to itunes, when i do so it tells me i need to update the iphone. The update starts but never ends and always gives me the same error of "the iphone "iphone" could not be restored. An unknown error occured (9). Any help? thinking of taking it into an apple shop tomorrow