terms aren't populated in sales order

When I create sales order using suite talk API "terms" are not added automatically although they are set in customer .
And when I tried to insert them explicitly I receive "Please enter a payment method" error message.

Any help of how can I get them populated either automatically or explicitly.

This is my code:///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
var salesOrder = new SalesOrder
{
entity = xxxxxx,
shipDate =xxxxxx
shipDateSpecified = true,
itemList = xxxxxx,
customFieldList = xxxxxx,
};

salesOrder.terms = new RecordRef //Set terms explicitly
{
type = terms.type,
typeSpecified = true,
internalId = xxxxx,
};

var response = netSuiteService.add(salesOrder);
// response.status.isSuccess = false;
// response.status.statusDetail[0].message = "Please enter a payment method"