So I updated my carrier file to enable the tethering, and my phone is all screwed up. It's not ringing when I get phone calls, or my visual voicemail isn't working. I'd just like to revert back to what I had. I keep seeing posts telling me to go to Users->User->Library->iTunes->iPhone Carrier Support but I don't have an iPhone Carrier Support folder anywhere within the iTunes folder. Where can I get the file?