Unable to cancel Adobe stock trial within the month, now says payment overdue

During the free month trial of adobe stock, I realized that I could not actually afford the service, so I canceled the service. However, a month later, I get an email saying they were unable to charge my previous credit card, and that my payment was now overdue. I checked my account, and found that stock was not in fact canceled. I don't plan on using any of the assets given, so how can I just end this?