Zoran,

There is a misplaced TEXT in your code. Instead of

TEXT TO soapEnvelope TEXTMERGE  NOSHOW
TEXT

<?xml version="1.0" encoding="utf-8"?>

prepare your SOAP call using

TEXT TO soapEnvelope TEXTMERGE  NOSHOW
<?xml version="1.0" encoding="utf-8"?>

Also, beware that your document must contain only simple characters or valid UTF-8 sequences for. Any character outside 0-127 range that is not properly encoded will invalidate the XML document.