Calling magento webservice from iOS just returns wsdl

I use the following code to make a first call to the magento webservice, it is a login (I used this doc)

NSString *soapMessage = @" \
<?xml version=\"1.0\" encoding=\"UTF-8\"?> \
<SOAP-ENV:Envelope xmlns:SOAP-ENV=\"http://schemas.xmlsoap.org/soap/envelope/\" xmlns:ns1=\"urn:Magento\" xmlns:xsd=\"http://www.w3.org/2001/XMLSchema\" xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\" xmlns:SOAP-ENC=\"http://schemas.xmlsoap.org/soap/encoding/\" SOAP-ENV:encodingStyle=\"http://schemas.xmlsoap.org/soap/encoding/\"> \
    <SOAP-ENV:Body> \
        <ns1:login> \
            <username xsi:type=\"xsd:string\">user</username> \
            <apiKey xsi:type=\"xsd:string\">password</apiKey> \
        </ns1:login> \
    </SOAP-ENV:Body> \
</SOAP-ENV:Envelope>";

NSURL *url = [NSURL URLWithString:@"http://localhost/magentoPath/api/soap/?wsdl"];
NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url];
NSString *msgLength = [NSString stringWithFormat:@"%d",[soapMessage length]];
[request addValue:@"application/soap+xml; charset=utf-8" forHTTPHeaderField:@"Content-Type"];
[request addValue:@"localhost/magentoPath/" forHTTPHeaderField:@"SOAPAction"];
[request addValue:msgLength forHTTPHeaderField:@"Content-Length"];
[request setHTTPMethod:@"POST"];
[request setHTTPBody:[soapMessage dataUsingEncoding:NSUTF8StringEncoding]];
NSURLConnection *connection = [[NSURLConnection alloc] initWithRequest:request delegate:self];
if(connection){
    self.webData = [NSMutableData data];
}
else
    NSLog(@"theConnection is null");

later on I have the following method which logs the response I get. The problem is, I always get the content of the wsdl, but I should get a session ID from magento. What am I making wrong? Thanks!

-(void)connectionDidFinishLoading:(NSURLConnection *)connection
{
    NSLog(@"Done. received Bytes %d", [self.webData length]);
    NSString *xml = [[NSString alloc] initWithBytes:[self.webData mutableBytes] length:[self.webData length] encoding:NSUTF8StringEncoding];
    NSLog(xml);
}

By the way, the request xml is from PHP's SoapClient where the login works correctly. So it has nothing todo with Magento.

So I found the solution myself after looking into the logs of magento. It says that you don't need to declare the xml every time, so just delete

<?xml version=\"1.0\" encoding=\"UTF-8\"?>

from the request and it works!