There is a similar sounding provision in GDPR, which requires that it is as straightforward to withdraw consent as it is to grant it (i.e. it must be possible through the same procedure, so preventing postal letters being sent to a dedicated address). Not sure if there's a similar provision for cancelling paid services, but potentially if the service relies on consent for data processing, you could use GDPR grounds to force a cancellation through the same means you signed up.