Ways to stop abuse of trials

Is there a way to stop people abusing the trial periods?
I did have a 3 day trial setup, which then automatically started payments after. Most went well, but had quite a few customers using the trial, stopping the payment, then starting a new trial a couple weeks later. I was hoping there would be a setting to stop them doing this, or at least stop them from doing it from the same account / email address, but couldn’t see anything.

I have S2 member pro, but I use the free version as it works better for us.

You might want to add a conditional there. In the button/form for your product, include a ccap to indicate that the user has already requested the trial (maybe a ccap like TRIAL), and then, on the page, only show the button/form to those without the TRIAL ccap, and for those with it, display a specific message about it.

Of course, it will work only if the user is logged in, so s2M can check their ccaps. And of course, someone can also create a new account if they really want to. But overall, it could be a way to reduce those multiple trials.