Somebody must have stolen my phone. I need to block my Vivo S7.
Android has the facility to block the phone from being used and erase the data remotely. But to avail this feature, you need to have a passcode set on your phone, and have the device manager enabled on your phone. If you have it enabled, you can simply log in to your Google account and then run the device manager on the web. This will allow you to track your phone and also erase it remotely.