<system.serviceModel>
        <bindings>
            <customBinding>
                <binding name="ZINTWS0018binding">
                    <mtomMessageEncoding messageVersion="Soap11WSAddressing10" />
                    <httpsTransport authenticationScheme="Basic" />
                </binding>
                <binding name="ZINTWS0018binding_SOAP12">
                    <mtomMessageEncoding />
                    <httpsTransport authenticationScheme="Basic" />
                </binding>
            </customBinding>
        </bindings>
        <client>
            <endpoint address="http://34sapqa6.arkas.com:8000/sap/bc/srt/rfc/sap/zintws0018/120/zintws0018service/zintws0018binding"
                binding="customBinding" bindingConfiguration="ZINTWS0018binding"
                contract="SAPServiceRef.ZINTWS0018" name="ZINTWS0018binding" />
            <endpoint address="http://34sapqa6.arkas.com:8000/sap/bc/srt/rfc/sap/zintws0018/120/zintws0018service/zintws0018binding"
                binding="customBinding" bindingConfiguration="ZINTWS0018binding_SOAP12"
                contract="SAPServiceRef.ZINTWS0018" name="ZINTWS0018binding_SOAP12" />
        </client>
    </system.serviceModel>

client.ClientCredentials.UserName.UserName = "***";
client.ClientCredentials.UserName.Password = "***";