Payment Servired repeat orders

With the payment module servired.php if a user enters an incorrect credit card they get redirected to Cs-Cart with the correct error messag, however if they wish to try again to make the payment (maybe they just made a typo) then they instantly get an error message “order number repeated” on servireds side "the order number/auth number) has to be unique.

Anybody any ideas of a work around, My php skills are none existant, I have tried prepending a random number to the order number sent to servired

servired.php line57

if (strlen($_REQUEST['order_id']) > 6) {
$order_n = rand(11.99 . $_REQUEST['order_id'] . (($order_info['repaid']) ? ('x'. $order_info['repaid']) : '');
} else {
$order_n = rand(11.99) . str_repeat('0', 6 - strlen($_REQUEST['order_id'])) . $_REQUEST['order_id'] . (($order_info['repaid']) ? ('x'. $order_info['repaid']) : '');

this gets around the “order number repeated” error on servired's side, allowing a user to have another attempt to enter a valid Credit Card but unfortunately falls down on the callback after successful payement.