We have a formal bug submission programme is hosted and provided by Hacker One-
https://www.hackerone.com
If you believe there is a security weakness in Fanatical.com that's been missed then we welcome you to signup to our programme and post your submission.
Reporting bugs scraped from other 3rd party bug bounty sites
Sometimes low risk bug reports are scraped from 3rd party bug bounty sites and submitted to us. These reports are often rejected as they have been previously discussed by our team and mitigating measures have been put in place around the discovery.
We want Fanatical.com to be as secure as possible so thank you for taking the time to get in touch.