Refund And Cancellation Of Unauthorised Deduction By PDF Guru

I purchased a one-time subscription for the PDF Guru PDF merger for $1 through their website. Despite clearly choosing a one-time purchase, today an amount of $49.99 has been reserved/charged on my account without my approval, which indicates that a recurring payment or different subscription has been initiated without my clear consent. I have not yet contacted Pdfguru support or my bank about this issue. I request that the $49.99 amount be fully refunded and that any active or recurring subscription linked to this purchase be cancelled immediately so that no further charges are taken from my account. I expect written confirmation that the refund has been processed and that my subscription has been completely cancelled.