Are we able to see why a payment failed?
There are a few places you can check.


Foremost, I would check your payment processor's logs.  Most likely the cards were sent there and declined.  Make sure you don't have any configuration mismatches - e.g. not allowing credit cards from outside your country, or requiring a CVV on the payment processor but not on CiviCRM (though I believe it's mandatory in CiviCRM on the front end these days).
Check your CiviCRM logs.  Their location varies by CMS.  If you're not sure how to interpret them, you may want to open a new question.