Any hope for a refund?

Probably a weird case, but I just want to check if anyone knows a solution: 

In summer 2023 I made a creative cloud subscription. I needed it for a job, but I was still a student back then so I got a discount. The email address that I used for the subscription belonged to my university. When I left that university in fall of 2023 I lost access to that address.

That the subscription was still running was something that I noticed only yesterday, when I saw it on my credit card bill. Up until then I was sure that I had canceled the subscription, then thought I must’ve made a mistake.

I then tried to log into my account but whenever I tried to get to the page where I could cancel the subscription I got an error message ("an error occurred"). I could see, however, that I had been billed for the subscription two times - with the regular price.

I then turned to customer service, because I wanted to get a refund. I hadn’t used any of the products since that summer job in 2023 and wasn’t intending to use them this year. I figured this would be visible in the system, so I didn’t think it was going to be a problem. The system’s entries seem to match my story, except for one single entry: They told me, that the products had been used two weeks ago. I told them it was impossible, but they insisted that the system showed that activity. They also told me that - because of that single activity that I couldn’t recognize - a refund was impossible in that case. Not only for the 2024-25, but also not for the coming year, although the subscription had only been renewed yesterday. I then asked them to send me a screenshot of the entry of the unknown activity to my private email, since that’s literally the only “proof” that I used those products (I know for a fact that I didn’t use them, but of course I can’t prove that). It’s also the reason they stated for why I can’t get a refund on any of those two periods. When I asked if there were any other activities, they said no. This was the only one.

They said in our chat they would send it to me, but now I got an email saying that they could not send me that screenshot.

To sum it up:

I had no knowledge of that subscription because I didn’t have access to that email address anymore after I left that university. The email address clearly belongs to an institution, but I still got billed both times for the regular price.. When I tried to login to manually cancel the subscription it wouldn’t work.

I haven’t used any of those products in the past two years and according to customer service, the system’s entries seem to agree with that - except for one single random activity from two weeks ago that I don’t recognize. Yet that one entry is the single reason for why I can’t get a refund for either of those two billing periods. However, when I asked for proof that that single activity exists, I couldn’t get it.

I understand that this is a special case, but I still don’t see how this could be happening. Isn't there any way out of this? Why can't I at least get a refund for the coming year?