XML : Soap request with Savon gets BEA-380001: Internal Server Error

I want to create xml request like this with Savon:

  <soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:prod="http://productservice.services.bcldb.com">   <soapenv:Header/>     <soapenv:Body>       <prod:productBySKURequest>          <prod:sku>42</prod:sku>       </prod:productBySKURequest>     </soapenv:Body>   </soapenv:Envelope>    

This is what I am doing in Rails console:

   client = Savon.client(wsdl: "http://esb.dev.bcldb.com:25011/LDB_Retail/ProductService?WSDL")     

And here after calling I get BEA-380001:Internal Server error:

  response = client.call(:get_product_by_sku, message: { "sku" => "42" })