One time payments

Description

Is there a way to pay someone 1 time only when I want the service and then block them when I don’t?
I want to sign up short term with Ancestry.com but they don’t cancel when you ask them to. They stole 200.00 from me a while back after I cancelled and I could only get 100 back. They won’t accept a prepaid card or check because they are an « auto renewal service ». It’s not worth the money to me to keep it active year round.