Find my Iphone Still Connected After being Removed

Just purchased a phone from someone used... It came and I went to activate it but it said it was still connected to the guys find my iPhone. I contacted him and he removed it from his find my iPhone... It's still saying I need to sign in with the original Apple ID that was used to set the phone up... It's saying it needs an email that is (C*****@yahoo.com) I talked to the guy on the phone and he never had or has a yahoo email account. He bought the phone new and set it up at the verizon store with his apple ID and password... I've put the phone into recovery mode and tried restoring it.. updating it. It's still showing up with the issue. Any ideas for what to do?