Help & troubleshooting for channels on your Roku device, including adding/removing channels, logging in to, authenticating, or activating a channel, channel-specific playback issues, assistance contacting channel publishers to report issues, and adjusting channel-specific settings.
First, understand that when you subscribe through Roku, you can only use that subscription through Roku. That means you can't log in on a Web browser or other device (phone, tablet, non-Roku streaming device) and utilize the subscription. It's how Roku does it, and one thing I really hate about Roku's way of doing things.
However, I remain a fan of Roku because I've found the devices and service overall to be top notch. But I won't subscribe through Roku. Rather, I'll subscribe directly to a service and use those credentials to authenticate on Roku -- or on phone, tablet, or other streaming device.
Now, from the way I'm reading things, you're doing everything right (well, trying on a browser won't work, but now you know that won't work with a Roku-based subscription).
Go to https://my.roku.com/ and log in. Ensure you're using the same email address that you see when you go to Settings > System > About.
Assuming you do see the subscription listed, I think you have two options: 1) work with @RokuDanny-R or other Roku personnel to resolve it, or 2) cancel the Roku-based subscription and subscribe directly.
DBDukes http://www.dbdukes.com/Roku Ultra (4660) Roku Streambar (9102) Roku Streaming Stick+ (3810)