You are entitled to ask for a refund in the timeframe of maximum 60 days from the day of purchase. However, I've visited the official website with hope to find the refund page or link or at least the policy for this procedure, but there is nothing available.
The only thing close to contact is an email: firstname.lastname@example.org
You should email them from the email account that was used to purchase the software and ask for a refund. If they refuse, contact the bank or PayPal and open a case.