I know you've made a post before about Comic Con Connections, so maybe you could share this? If not that's okay, but maybe it will help people like me who can't get a response or a promised refund.
If you are having issues actually receiving your refund from Comic Con Connections, you can file a complaint against the company.
To complain about a limited company:
https://www.gov.uk/complain-company
Comic Con Connections is organised/hosted by KTEG Limited (confirmed via the charge on my bank statement). Their information is:
KTEG LIMITED
Company number 08692884
(That information is public, and was located via gov.uk at https://find-and-update.company-information.service.gov.uk/company/08692884)
This is excellent information, and anyone who needs to should absolutely look into it.
Thank you for sharing this. I hope it helps the people who need it.