Step 1: Go to Settings>General>Reset>Erase All Data and Settings, enter the password to confirm it. IPhone call history recovery free with iTunes or iCloud backup file, it's better to backup iPhone data to iTunes or iCloud in advance, all data on iPhone will be replaced by backup file.
Tip 1: How to Recover Call History on iPhone Without Computer
How to undo call history on iPhone without computer? Restore from iTunes/iCloud backup files, but we can't select part of data on backup file but all data on backup files and all data on iPhone will be overwritten by the backup file, if only call history we want to get back, use EelPhone iPhone Data Recovery to undelete lost call logs, select call logs from scanning result.