I cannot complete the order, although I have checked my payment details more than once. What is the problem?
The problem might be concerning an incompatibility between the payment method chosen and the currency set in your order. For example, pounds are not supported by Authorize.net.
Is there a way to limit users choice to specific types of credit card?
No, this possibility is not conceived. Users will be able to pay using any card within Authorize.net circuits (Visa, Mastercard, American Express, Discover, Diner’s Club, JCB). You may lead users to think there is a limitation concerning credit card systems available, by displaying only logos of some of them.
Why doesn’t the authorize.net receipt show the product that was ordered? It only shows the order number and amount
You will be able to send the detail of products purchased to Authorize.net via API., but to make this work correctly just make sure you select the option Enable itemized transaction in the plugin settings. You can read more about this feature here.