Pdfbilling.com Unauthorized Mastercard Charges

For several months I have been seeing an unauthorized charge of €49.95 on my card from pdfbilling.com. I live in Belgium and the payments are taken from my Mastercard. The first payment appeared in June, and since then the amount of €49.95 has been taken three times in total, without my permission. I never requested or knowingly started any subscription with pdfbilling.com, and I never received any email, confirmation or information about such an abonnement. I only recently noticed these repeated charges and I have not yet been able to contact my bank or the company about them. I consider these payments unauthorized and I want the subscription, if any exists in my name, to be cancelled immediately and all unjustified charges of €49.95 refunded to my card. I ask for a quick investigation into how my card details were used, a full refund of all unauthorized payments, and written confirmation that no further charges will be made.