Shortmax Subscription Not Showing In App

I am using the Shortmax service in England and I want to cancel my subscription immediately, but I am unable to do so. I am paying for this subscription by credit card, yet when I log into the Shortmax app I cannot see the phone number or any subscription information linked to my account. The subscription section appears empty, so I have no way to manage or cancel the active subscription. I first tried to cancel my subscription through the app yesterday, but since my subscription details do not appear at all, I am stuck and cannot proceed with the cancellation. I have not yet contacted customer service or my bank, because I expect to be able to cancel directly through the app where I started the subscription. I request that my Shortmax subscription, which I am paying for by credit card but cannot see in the app, be identified and cancelled immediately, and that I be informed clearly about the process.