You should be able to receive multiple attachments. All the attachments' data must be present in pyRequestAttachmentPage, specifically, in value list properties, pyAttachNames and pyAttachValues. If you aren't seeing data of all the attachments, please raise an SR so that someone from the GCS can guide you through the configuration.
You could also use a tool such as TCPMON to check if all the attachments are correctly transferred over the wire.
Prasad, I'm able to replicate the issue you reported here using soapUI with default options. However, when I set this request property Disable multiparts to false, I don't see the error anymore and I'm able to consume the attachments.