Unauthorized Debit

I have logged on the PluralSight (https://www.pluralsight.com/) in quest of trying there free subscription and evaluate my option to adopt this in my environment.

Site require Visa account to try it out and i did share the details. however i was shocked when my account was debited in December and I queried it with my bank however they could not reverse the money because is was on pending state. January they have debited again!! i am not happy with this as i did not signed up for it.

Regards, Thabiso