Hi,
unfortunatly, you can't, unless the values are hardcoded inside your project and built with these.
if the user saves a different value, it will be saved in the playerprefs, and deleting the prefs makes it unrecoverable. you could save data online on a server, then if you have a user management system you can recover data even of the user plays on a new phone or has deleted and reinstalled.
Bye,
Jean