The article mentions a case where Amazon Prime membership wasn't refunded. The Amazon Prime terms state that it would be refunded on termination. However, it also has the following term:

However, we will not give any refund for termination related to conduct that we determine, in our discretion, violates these Terms or any applicable law, involves fraud or misuse of the Prime membership, or is harmful to our interests or another user.

IANAL, but would that not constitute an unfair contract term under UK law?