ShortMax Cancelled Subscription Still Charged Twice

I subscribed to ShortTV / ShortMAX on March 26 with a test promotional subscription of USD 1.99 at 3:11 pm. On the same day, March 26 at 10:03 pm, I sent an email to [email protected] requesting the cancellation of my subscription within the first promotional 24 hours, before any regular subscription billing started. Despite this clear and timely cancellation request, on March 27 at 3:11 pm I was billed USD 19.99. After noticing this, I sent a second email on March 28 at 3:28 pm reinforcing my cancellation request, and then a third email on March 29 at 9:50 pm, again asking for cancellation and correction of the charges. I only received automated responses stating that the issue would be solved within three days, but no real action was taken. On April 3 at 3:11 pm, I was billed yet another USD 19.99. In total, there have been two incorrect charges of USD 19.99 each, adding up to USD 39.98, even though I requested cancellation in time. Additionally, the ShortTV / ShortMAX app does not appear on my iPhone in a way that allows me to cancel the subscription myself, which leaves me dependent on the company to process the cancellation. I request that my subscription be considered cancelled as of my first email on March 26 at 10:03 pm, that all further billings stop immediately, and that both incorrect charges of USD 19.99 on March 27 and April 3 be fully refunded. I also ask for written confirmation that my subscription has been cancelled and that no further charges will be made to my account.