Credit cards icon is included into Business Icon Set. You can view all icons here:[link]
Each icon is available in sizes of 16x16, 24x24, 32x32, 48x48 and 256x256 pixels. All images are supplied in ICO, PNG, GIF, and BMP formats. Your order will get you all icons in have 256 colors and True Color variants. The entire set of over 254 icons is available for only $99.00.
Download link: [link]