Hello!

Thank you for reaching out,

We are sorry to hear you have been unable to log in to your Mozilla VPN subscription. Try setting Firefox as your default browser and try signing in again, this could solve your issue.

If you would like to cancel your Mozilla VPN subscription, you can log in to accounts.firefox.com with the Firefox account associated with the subscription, next to subscriptions, click on manage and you will have the option to Contact Support. Send us a refund request through this option and we will gladly assist you.

I hope you find this helpful, and please let me know if you need anything else.

I too am having this issue. I've been getting charged monthly since February for the VPN service. I get the same error "not a subscriber" as the original poster and can't download the client to ask for help. The link you provided to the accounts page does not mention 'subscriptions', won't allow me to manage anything and will only allow me to sign out of connected services. Please assist! Thanks!