Required custom field for CashSale

I am trying to submit a CashSale through the SuiteTalk PHP Toolkit. A required field for the custom form I am using is End User (custbody_end_user) which points to a Customer record type. Here is part of the code I am using:
[PHP]
$cs=new CashSale();

$enduserField = new SelectCustomFieldRef();
$enduserField->value = new ListOrRecordRef();
$enduserField->value->typeId = '-2';
$enduserField->value->internalId = 46422;
$enduserField->internalId = 'custbody_end_user';

$cs->customFieldList = new CustomFieldList();
$cs->customFieldList->customField = array($enduserField);
[/PHP]


Which returns the following error:
[PHP]
[statusDetail] => Array
    (
        [0] => StatusDetail Object
            (
                [code] => USER_ERROR