Yes, IVPN offers a 3 day free trial. You will need to signup using a credit card or PayPal but we will not charge your account until after the 3 day period expires. If you cancel during the trial period then you will not be charged anything.
In any case you entitled to a full refund within 7 days if you are not happy with the service for any reason. Simply submit a cancellation request and your full refund will be processed within 24 hours.