@lomony, this post discussed previously should help you achieve your requirement:
But feel free to reach us back if this still does not work. The other option is to use the dynamic data attachment feature that will block response (if some identifier variable) matches the record that is already there on the server. But please be informed that too cannot be controlled if a response is made within an interval of 5 minutes as the dynamic data attachment has a 5 minutes syncing time.
