This problem arises because the xpayments cron.php expects to be run "implicitly" from the command-line. You need to adjust your cron command to use the php cli binary directly.
Here is an example cron that we have used that runs the xpayments cron without issue on at least a dozen CPANEL hosted client installations:
Code:
cd /home/username/public_html/xpayments;php-cli cron.php
Of course, change the above example folder path to suit your own installation.