for every problem there is a solution.

which credit card module are you using?

in my auth.net module, look at these lines of code:

https://github.com/proseLA/authorize...im.php#L43-L46
https://github.com/proseLA/authorize...hp#L1003-L1024

this slows them down and then logs them off...

it is possible that you have a method for testing credit cards that is NOT part of the checkout process, which is why the slam protection might not work.

best