This is not so CIish ATM, and I know that. (just because it was done in a hasty attempt to give client work on time)

I will improve it when I can or anyone else can and send me Pull request :)

The Table I use to log transaction is:
CREATE TABLE `transactions` (
  `id` varchar(16) NOT NULL,
  `amount` float(10,2) NOT NULL,
  `created_at` datetime NOT NULL,
  `cardholder_name` varchar(64) DEFAULT NULL,
  `card_last_4` int(11) NOT NULL,
  `status` varchar(32) NOT NULL,
  PRIMARY KEY (`id`)
) ENGINE=MyISAM DEFAULT CHARSET=latin1 COMMENT='latin1_swedish_ci';