In some cases, this might be your app? Past a certain point, "take them to court or threaten to do so" can actually be easier than dealing with the company directly. Or, though it's a bit riskier, cancelling your payment mechanism and disputing things if they try to send you to collections or ding your credit score.

The much-maligned Google assistant did sound tempting for this, though. Something willing to call every single day and sit on hold indefinitely to convey a simple message would be awfully useful for the less-illegal forms of membership stonewalling.