Can't process credit cards

I recently switched credit card processors from WorldPay to Authorize.net - so I plugged in my authorize.net credentials into the website settings in the admin panel, and am no longer able to process cards of any kind. The POS system gives me a general declined message, same with when I try to run an order in the admin panel. I’ve spent hours with customer support trying to get this resolved and no one seems to be able to help me. Would anyone have any insight into why it might not be working?

Call Alexia or Wendal at usaepay that will be more than happy to help you they ate wonderful.

Technically, Authorize.net and USAePay are payment gateways, not merchant processors. If the OP is using Authorize.net, she is likely not using Change Merchant Solutions and Wendell can only help if they are a client.