Code:
curl_setopt($ch, CURLOPT_CAINFO, DIR_FS_CATALOG . DIR_WS_MODULES . 'payment/cacert.pem'); // this is a temporary workaround for this hosting company. Remove this line once the hosting provider has fixed the configuration of PHP / cURL on their server!
You will probably need to specify the entire path to the CA Certificate bundle. So either hard coded with the full path for your specific server or something like the above. Adjust as necessary for where you saved the CA Certificate bundle.