Identify Roku as the actual seller
Midnight Pulp publishes a cancellation article specifically for Roku subscribers. Use it when the membership is billed through Roku. Begin with the receipt or subscription record rather than the device on which you most recently watched; viewing on Roku does not by itself establish where a payment originated.
Keep the product and purchasing account together. If the subscription does not appear in the first account you inspect, compare the original confirmation before changing unrelated service accounts. The question is which seller controls this payment.
Use the management action
The documented remote route highlights Midnight Pulp, opens the options menu and selects manage subscription followed by cancel subscription. The article also describes signing into the Roku account on the web and using its subscription-management area. Follow the current controls presented by that account.
Check the resulting state and retain the confirmation or displayed end information. A channel disappearing from a home screen is a different observation. The useful evidence is whether the billing subscription changed as intended.
Keep any follow-up tied to that record
If a later payment is unclear, use the seller, subscription state and transaction reference in the official enquiry. Do not infer a refund or a particular remaining viewing period from an older help article’s general wording. Read the account’s current record.
This workflow should not be applied to a membership bought directly or through another app store. Identify that seller instead. Removing and reinstalling the viewing app does not answer the unresolved billing question and need not be the first response.
Questions answered
Does watching on Roku prove Roku billed the subscription?
No. Check the purchasing confirmation or subscription record.
Which result should I retain?
The actual subscription state or cancellation confirmation, rather than only a changed home-screen tile.
Sources & further reading
Official references for the subjects discussed. Service terms and device software can change.