Stolen

If your iPhone, iPad, or iPod touch is lost or stolen - Apple Support

This is a user-to-user forum. No one here knows who you are, and no one can “delete” your IMEI. You can ask your carrier to blacklist your IMEI, but blacklists are not honored worldwide.

And there’s no point in notifying Apple of the theft; they cannot and will not do anything about lost or stolen devices. See the link by sberman for what to do next.