Apple doesn't justify its decisions. I know you may not like that but it's how they do things. In particular with subscriptions it is fairly common to see complaints here about refused subscription refunds. I don't know who is involved in the decisions or how they arrive at them.
Apple does not have much on its criteria for refusing refunds. Below are two sections from the U.S.A. version of Apple Media Services Terms and Conditions - Legal - Apple Media Services - Apple You can see if the terms are different for where you live by clicking on this link Legal - Apple Media Services - Apple then select your location and then your language.
- "All Transactions are final."
Apple's terms of purchase in the USA are, "All Transactions are final," ( Legal - Apple Media Services - Apple section B), but check the terms for your country. Even if Apple does not outright say in a country that sales are final, they may say that refunds are only made to remedy defective or unavailable product. In other cases Apple may make limited refunds solely at their discretion and as an exception. Apple can also simply say no without having to provide a reason. I understand this can be frustrating but by using the service you agree to the terms.
- "From time to time, Apple may suspend or cancel payment or refuse a refund request if we find evidence of fraud, abuse, or unlawful or other manipulative behavior that entitles Apple to a corresponding counterclaim." Remember that Apple has no way of removing a purchase from your device. They have to trust you are being honest when asking for a refund. It may be that certain refund requests might be considered suspicious or excessive.
According to https://reportaproblem.apple.com/static/en-us/privacy.html , Apple uses an automated system to detect fraud. Your request may not have met the automated system’s criteria for a refund. If you feel you want to discuss a refund request with a person, try to contact an Apple representative by email —> “If you disagree with your final decision, contact dpo@apple.com “ However, according to user reports, the wording of that document may be a bit misleading because the automated response talks about privacy issues, not refunds.