If you are unable to find your contacts which were stored on iCloud, then try this --> Restore contacts, calendars, bookmarks, and more using ...
Check if the email account has been removed from the iOS mail app.
Add the email account that stores your contacts in the IOS mail app and enable Contacts.

What is your default Contacts account? If none, please add an email account and enable contacts.
See the pic below
Unlike some Android devices, contacts are neither stored locally on an iPhone nor in SIM. They are synced to an email account that you had Google, iCloud, AOL, Exchange, Outlook, Yahoo or any Other

If you have a corporate email account added through a profile on your device, please check with your organization's system administrator.
