How do I cancel my Duda subscription?

I paid to use Duda as the mobile version for our website, but was then informed by a Homestead representative that Homestead had created a newer website builder that would not require a Duda subscription to have a mobile-friendly site. I re-created my website using websitebuilder, but was still charged for Duda, even though I am no longer using it whatsoever. 
How do I stop this from happening/get my money back from Duda?