HT4061: iOS: How to find the serial number, IMEI, MEID, CDN, and ICCID numberLearn about iOS: How to find the serial number, IMEI, MEID, CDN, and ICCID number
The article that brought you here has many suggestions. Did you try all of them? Here's one more:
http://support.apple.com/kb/HT2526 - If you registered a device you can use My Support Profile to find a list of serial numbers that have been purchased or registered with your Apple ID.
The serial number is only useful for reporting the stolen item to the police, your insurance company, not to Apple. Apple will not help you recover the phone.