Phone contacts replaced by e-mail contacts
Hi there. I'm a new iPhone user. I bought an iPhone 4 (8GB) on Friday, October 14th. Verizon was able to sync my phone contacts from my old Chocolate 3 to the iPhone, no problem. The problem now, just a few days later, is that my Yahoo e-mail contacts have completely replaced my phone contacts. Even in my call log, entries are now listed by the actual telephone number instead of the name of the person I was talking to. I am not using iCloud, by the way. My syncing is done manually by plugging my iPhone into my iMac and using iTunes.
I suspect that I can go to a Verizon store (again) and have them transfer the contacts from my old phone (again). I'd rather not, though. Is there a way to fix this at home?
Of far more importance, how do I stop this from happening again?
iPhone 4, iOS 5