Thanks for reaching out to Canon USA, we're happy to help!
The serial number on your VIXIA camera is going to be on the bottom near the tripod mount, just below what looks like a QR barcode like this:
If you've tried that serial number, you'll want to reach out to Support. The phone number here in the US is 1-800-OK-CANON (800-652-2666). Video support is open from 10am to 10pm (ET) weekdays.
Outside of the US, click HERE to find support options for your country.