PDF Guru Refund Request for Unauthorized Debit Without Prior Notice

I was charged 71.53 CAD without any prior notice by pdfguru.com. I had only subscribed for a 7-day plan, and the payment was already debited from my account. However, I did not renew the subscription, so I don’t understand how they charged me again without informing me first. I am addressing this to pdfguru.com and kindly requesting a refund.