Yes, you can store multiple credit cards at the same time. To add a credit card to your A-Suite Ad account, visit the Ads tab at the top of your page, then click the Ad Dollars Available button next to + NEW AD. From there, either choose a pre-determined amount of Ad Dollars or type in a specified amount of Ad Dollars. Then, click CONFIRM PURCHASE and fill out your credit card information.
If you have multiple credit cards in the system, you can choose which credit card to use at the time of purchase in A-Suite Ad.