PHP SoapClient - action in the wrong place - php

Question

I'm using PHP SoapClient, and am running into an issue with getting the request format just as a third party wants it.
They want it like this:
POST /service.asmx HTTP/1.1
Host: service.com
Content-Type: application/soap+xml; charset=utf-8
Content-Length: length
<?xml version="1.0" encoding="utf-8"?>
<soap12:Envelope xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:soap12="http://www.w3.org/2003/05/soap-envelope">
<soap12:Body>
<Order xmlns="http://someservice">
<json>string</json>
</Order>
</soap12:Body>
</soap12:Envelope>
However, the closest I can seem to get it, using SoapClient, is like this:
POST /service.asmx HTTP/1.1
Host: service.com
Content-Type: application/soap+xml; charset=utf-8; action="http://someservice"
Content-Length: length
<?xml version="1.0" encoding="utf-8"?>
<soap12:Envelope xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:soap12="http://www.w3.org/2003/05/soap-envelope">
<soap12:Body>
<Order>
<json>string</json>
</Order>
</soap12:Body>
</soap12:Envelope>
Notice how the action in my request is in the http header, and the action in their ideal format is in the Order tag. The thing is, it's SoapClient that is generating where that action is being placed - it gets that specific url from the WSDL, it's not even in my code.
How do I tell SoapClient to put it in the right spot? For my part, trying to only include what's necessary, this is essentially the code:
$this->client = new SoapClient($this->wsdl, array(
'soap_version' => SOAP_1_2,
'encoding' => 'UTF-8',
'stream_context' => stream_context_create($context),
'trace' => true,
'exceptions' => true,
)
);
$json = json_encode($request);
// Prepare the xml
$xml = array();
$xml[] = new SoapVar($json, XSD_STRING, 'string', 'http://www.w3.org/2001/XMLSchema', 'json');
$this->finalXML = new SoapVar($xml, SOAP_ENC_OBJECT, null, null, 'Order');
$this->response = $this->client->CreateOrder($this->finalXML);

Answer 1

After days of banging my head, I found this and ended up making the accepted, hacky solution work for me:
Change SOAP request format
Apparently, when you're working with a poorly written Soap API, there's not a lot you can do.