I launched Friday night and a friend and new customer have tried to use credit cards. I have my 3rd party set up and looks all good in Shopify. Transaction Key set up. API set up. Authorize.net is just not seeing the transaction and Shopify is showing code E00028 and E00007 as the full response code.
There was an issue processing your payment. Try again or use a different payment method. is what is shown to customers and me when I try to use cc.