Authorize.net can be setup so you can charge credit cards, and issue credit card refunds on phone orders. From the Company Settings menu, go to 'Payment Settings' and then click the 'select CC processor' button. On the next page, select Authorize.net and then click the edit link to enter the credentials from your Authorize.net account. You will need a username and transaction. These credentials can be obtained by logging into Authorize.net and navigating Account > Settings > Security Settings > General Settings. Click on API Login ID and Transaction Key.
When setting up Authorize.net for SellerCloud be sure to enable the Transaction API:
When using Authorize.net for eBay orders, enter the same credentials under eBay Settings > Authorize.net. The credentials need to be entered in both locations for eBay orders.