PayPal is committed to providing you with the most advanced technical support expertise to ensure availability and reliability of your e-commerce applications. For details, refer to your Service Level Agreement.
For integration and connectivity issues, PayPal provides online documentation, direct email support, and phone support.
Online Information: https://www.paypal.com/us/cgi-bin/helpweb?cmd=_help.
This site contains a "frequently asked questions" section.
Documentation: The Documentation link (available on the top right side of all PayPal Manager pages) provides access to printable copies of PayPal Manager documentation.
For technical support on shopping carts, contact the merchant.