What to do when free trials don’t work?

I run a business summary app with subscription prices of $50/year and $6.99/month. Unfortunately, some people sign up for the free trial that I offer but they use fake cards. So after 7 days the charge doesn’t go through. What can I do about this? I’m using stripe and Nodejs. It’s really frustrating because customers only want free. You try to charge but they insist on a free trial and when you give them that they abuse it. I guess I can do a money back guarantee but they don’t like that too. What do you guys think?