I had been subscribing to CBS All Access on my Roku, but I recently purchased a smart TV and no longer use the Roku. I let the CBS subscription expire (it expired yesterday) and then deleted my Roku account, so I can no longer log in to Roku.com. Yet, CBS still says I'm subscribed through Roku and won't let me subscribe directly through their website (even though the subscription is expired, I can still watch CBS All Access for some reason). I need to break the link between CBS All Access and Roku so I can subscribe to CBS directly through them.
I can't speak to CBS All Access directly, but most of these streaming subscriptions auto-renew every month until you explicitly cancel them. In other words, they don't just expire. This is all spelled out in the conditions you agree to when subscribing.
If you subscribed via your Roku account (rather than directly with CBS) and then canceled your Roku account without first canceling your CBS subscription, I don't know how you can now go about canceling CBS.
Hopefully one of the Roku reps here will see this thread and offer to help.
Roku Streaming Stick +, 3810X, Ser YH0059427035, wifi LivRm - Samsung UN55ES6100
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Roku 3, 4200X, Ser 4124C7087583, wifi GstRm - Sanyo DP26640