If a customer places an order on a website but their payment method is refused, it is acceptable to contact them via email to either enquire if there was an issue or to offer them an alternate method of payment? Maybe offer them a gift voucher for having problems, for example?
You should be contacting any customer that abandons there cart at any point in the checkout process. If they have a large order, and entered there personal information, then they are ussually serious about ordering, but got spooked.
Sometimes a customer will abandon the cart, at the shipping charges screen. If you check the cart and its a large order, you may want to offer free shipping, to save the order.
in a week we get couple of payment attempts or account creations but no successful payments. and we immediately send emails to our members asking if they are having difficulties in sending us payments, we ask for their contact number and as well leave our number so that they can call us at their most convenient time - try to assist them to whatever problems they might be encountering. for members who are really interested to buy from us, we can get like 80% of them after assisting them on how to pay (that's good customer service) , be prompt in dealing customer's difficulties. While the rest of the payments attempts no successful - those are from fraudulent buyers.