ShortMax Subscription Charged After Cancellation - Cannot Stop Billing

I am being repeatedly charged for a ShortMax subscription that I have already requested to cancel, and I am unable to manage or stop it through normal channels. I originally downloaded ShortMax through Google Play, but it has never appeared in my Google Play subscriptions list, so there is no option there to cancel it. Instead, the subscription fees are being charged directly to my bank account by Signal Financial Federal Credit Union. I first requested cancellation of this subscription on February 11, 2026. Despite this, I was charged again on February 25 and March 3. Since the subscription is not visible under my Google Play subscriptions and the charges come through my bank, I contacted Signal Financial Federal Credit Union for help. They only told me to call a phone number, which did not resolve the issue or stop the billing from continuing. I am requesting that the ShortMax subscription be fully cancelled immediately and that I be refunded for the two additional charges made after my cancellation request, dated February 25 and March 3, 2026. I also want written confirmation that the subscription has been canceled and that no further charges will be taken from my account.