did you try factory resetting in recovery mode?
you can try volume up + power button to enter recovery mode
ensure that you remember your google account registered on the phone, because you'll need it after factory resetting
Ng yare na yan sakin vivo v7 din cp ko dati laptop/pc talaga gamit ko gumamit ako ng miraclebox dun na open ko cp ko na try ko mag reset pero wala kwenta dahil yung google account ko nalimutan ko so Miracle Box talaga ginamit ko