How i can

If you weren't syncing Contacts to iCloud, do you have a backup you can restore from? Restoring from a backup erases all data currently on your device. Any data newer then when the backup was made will be erased. A restore is an all or nothing restore. You can't access a backup to see the contents and only restore certain files.

Backup - Restore your device from an iCloud or iTunes backup.    *

ASC YouTube for how to restore an iPhone, iPad, or iPod touch from an iCloud backup

ASC YouTube for how to restore your iPhone or iPad from a backup on your Mac

Hey there,

if you have a backup of that contact See this article ☞ Restore contacts stored in iCloud on iCloud.com - Apple Support

You’re service provider (you receive monthly bills) = those statements should list all incoming and outgoing phone calls.

If you have your monthly statements, you should be able to find the phone number. 😉

You’ll need to check your monthly phone bill to locate the phone number that you had deleted. 😉

You need to reach out to your service provider for the monthly statement.

The first two posts above are the only ways you can recover your contacts.