PDFcharge.com Keeps Charging My PayPal Mastercard After a One-Time Trial

I am writing regarding repeated charges made by Pdfcharge.com to my PayPal Mastercard after what was supposed to be a one‑time trial to sign a document sent to me in September. I only intended to use the trial service once and did not authorize any ongoing subscription or recurring payments. Despite this, Pdfcharge.com has been charging my PayPal Mastercard every month since September, including charges such as around $46 on September 5 and about $49.95 on October 5, plus additional similar amounts and even a pending transaction. I noticed the first charge in September and immediately tried to contact the merchant using the information shown, but I could not reach them in any way and had no access to manage or cancel any subscription. Since then, I have been reporting to PayPal that I cannot reach Pdfcharge.com and that these charges are not authorized beyond the initial trial use. I live in Puerto Rico, United States, and my PayPal account is also registered in the US. I feel this situation is unfair because I only used the service once as a trial, and there was no clear or accessible way to cancel or stop these payments, nor any effective contact information for the merchant. I request a full refund of all Pdfcharge.com charges that have been taken from my PayPal Mastercard since the initial trial in September, as well as the immediate cancellation of any subscription or agreement linked to my account and the blocking of all future payments to Pdfcharge.com. I also ask that this situation be reviewed so that similar unauthorized recurring charges do not happen again.