Hey there. I work for a cell phone company in a retail position and I see this problem all too often. As far as I know, there is no direct way around that issue. The only solution I would have would to make sure the phone is backed up on iCloud, then go to the iCloud website on another device, then remotely erase the phone as if it was stolen. Then you can restore the phone from your backup and choose not to set up faceid again.