wont connect to itunes

I stupidly updated my iphone 4s and now my WiFi no longer works! I returned my phone to the shop who in turn sent it back to apple to be fixed as this problem has occured quite a lot with the new update. I was then told by apple that they could not fix my phone as it is water damaged ! (not in a million years has it been near water)! To cut a long story short I have been advised to connect to itunes and restore my phone to see if this solves the problem BUT when I try and connect it tells me it cannot connect to itunes I need to reinstall itunes and download the 64bit version. I have done this numerous times and still coming up with the same message!!! anyone help?????