Two Payments Taken


I have an issue with CS-Cart; has anybody else had this issue/know how to fix it?

We had a customer place an order with their bank card which failed. They then received a payment failed email. They then paid via PayPal from another account which worked however money was taken from their card too so we recieved two payment.

Can anybody help with this so it does not happen in the future?

Any help/advice is appreciated.

Kind Regards