Cancelled Claude months ago; Just got charged $50 out of the blue - how to contact support???

I haven't touched Claude in months and had cancelled my subscription. The API had my card on file still, but I wasn't using it. Out of the blue I just got charged $50. When I logged into the API site, I saw my last use of it per their own logs was in 2024.

I used the "support" chatbot and it assured me that a human would reach out to issue a refund, but I haven't heard anything, and it said they don't issue ticket numbers, and I've gotten no email saying an issue is pending/etc. Needless to say, I'm doubtful about all of that AI generated response.

Is there any way for a human to help me resolve this?