There are (where) a bunch of scummy companies (dating sites, magazine subscriptions, ISPs) that have (had) an easy onboarding process, but you needed an notaris

There are (where) a bunch of scummy companies (dating sites, magazine subscriptions, ISPs) that have (had) an easy onboarding process, but you needed an notarised letter written with your own blood, send to them only on at full moon to end the subscription. If we only now could get the cheaper mobile plans new customers get, that would be nice. I really hate to ask once a year "Can I get the new plan?" "No, ok I will cancel my plan." Only to wait for their call back where they give me the cheaper/upgraded plan.