Php Tool Kit (Adding to a custom record error)

I'm getting the following error when I attempt to add to a custom record through php.

*The specified custom field key is missing

Here is my code...

// netsuite servic
$service = new NetSuiteService();


//create an instance of the fields of the custom record
$customFieldList = new StringCustomFieldRef();
$customFieldList->internalId = "custrecord_inv_phone_number";
$customFieldList->value = "333.222.1212";

$customFieldList2 = new StringCustomFieldRef();
$customFieldList2->internalId = "custrecord_inv_cust_number";
$customFieldList2->value = "4423234234";

$basicCustomRecord = new CustomRecord();
$basicCustomRecord->name = "Client Invoice Body";
$basicCustomRecord->recType = new RecordRef();
$basicCustomRecord->recType->internalId = "11"; //Record Type's internal ID (Setup > Customization > Record Types > Basic Record Type (Internal ID=14)