Please try the followings, if you fail to social login.If you know the E-mail address and passwordIf you know the E-mail addressIf you don't know both.
- Log in with your SNS account from your browser.
- From the menu in the lower right corner Settings > Edit profileand confirm your E-mail address
- From the menu in the lower right corner, select Settings > Change passwordand change your password
- Log in with your email address and changed password.