PDFSmart Unauthorised Deduction Of £49.99

I am a user from the UK, and I am writing to dispute an unauthorized charge made by PDFSmart. On 7 May, I subscribed to a 7‑day service for document conversion, believing it to be a one‑time or short‑term usage. On 14 May, £49.99 was deducted from my account without my clear authorization or awareness that this would become a recurring paid subscription. I did not know where or how to cancel such a subscription because I was not aware that I had entered into a continuous paid plan. After I noticed the £49.99 charge, I contacted you immediately to complain and to request a refund. Only after my complaint did you cancel the subscription, but my refund request was declined. During my communication with you, I clearly explained that I did not knowingly agree to a recurring subscription. I also asked you to provide evidence that I was clearly and prominently informed that the 7‑day service would automatically renew as a paid subscription for £49.99, but I have not received any response to this request. I am therefore formally disputing the £49.99 charge taken on 14 May and requesting an immediate full refund of this amount to my account. I also ask you to confirm in writing that my subscription is fully cancelled and that no further charges will be taken in the future.