How to cancel the restore process and get back the data?
my Husband using 6s plus. I accidentally restore his iphone wrongly but I didn’t back up beforehand.
You cannot cancel a restore that is in progress. If you restored the phone without a backup, then the data is lost. There is no way to recover something that is not backed up. If you did this restore over iTunes, it should have created a backup before the restore. You can check there. However, if you did not restore in iTunes, the data is gone.