The last thing you want is to have a credit card transaction be passed to the processor and then fail because of a customer typo. The latest version of CS-Cart as of today (4.14.2SP1) inexplicably fails to perform this basic validation, although there is already support in place. To get validation working, make a backup copy of your /design/themes/responsive/templates/views/orders/components/payments/cc.tpl file and then swap the existing script at the bottom with the following code:
Assuming that you aren't using a heavily modified template, this should work fine (tested for single page checkout). While you're tweaking the checkout, you might want to check out my post about auto-updating shipping options.
Obviously you accept any risk of breaking something (always make a backup) and if you're applying to a different version of CS-Cart, it may not work as-is.