Subscriptions System Confusing: Horrible Customer Service from a Supervisor at iTunes Support

I got a subscription to Crunchyroll on my iPhone back in August. I cancelled the subscription in September through the Crunchyroll website and even got an email confirming my cancellation! Lo and behold, 5 months later, I notice that the charges have still been going through my credit card all this time.

I got a refund on January's charge through the Apple website, but couldn't get it on any of the others.

I called Apple iTunes Support and they tell me that they can't refund any more of the charges because I should have clicked on all of them when I was cancelling them (I still don't know how I'm supposed to do that and that whole system is ridiculous anyways.)

I eventually get to talk to the supervisor over there and she immediately is annoyed with me. She starts explaining how the subscriptions are through iTunes and that you can't cancel them through the website as if I should know that. This is the first time I've subscribed for anything through Apple, so of course I don't automatically know all of this. Also, this is a really horrible way to treat first time customers, especially when these systems are not easily understood on your first go. I tell her that I received a confirmation email when I cancelled the subscription and haven't been able to use the content afterwards; for all purposes, I was unsubscribed. She says "That's something you need to take up with the developer," which is a really stupid thing to say since I've been paying Apple this whole time, not Crunchyroll.

I hadn't been talking to her for 2 minutes, when she starts raising her voice at me out of annoyance. I realized she may not even realize she's doing it, so I told her, "Don't raise your voice at me," and she starts raising it even more and talking over me. Then she says, "I've been playing nice with you for five minutes, now," and just hangs up on me!

This was the worst customer service experience I've had in my life. There's no easy way to make any kind of formal complaint, either, so they get away with this stuff. There's no judicial way for you to present your case, either. The whole time, they just kept repeating the same lines about what I did wrong and didn't listen to my point of view. I bet there are a lot of people out there who were taken advantage of for not knowing how their subscriptions work, too, because it's really not simple when you're a first time Apple user.

If anyone knows how I can get my refund or make my complaint properly, let me know. Until then, I'm going to start buying my music from somewhere else.