1) You mean the session is not ended or the script is still running? doing a hangup doesn't automatically end the script. You can do return 'exit' from the script (not from within a function in the script) to exit the script.
Even with return 'exit' the calling mobile phone is still connected to the PBX. I need to close the call hanging up all sides.
2) Why don't you put the entire functionality in the lua script using session:playAndGetDigits() and then use a goto if you want to ask again for the order number.
Good idea, i'll do in that way.