Here is one of the example of bot reply on incorrect user input.
While communicating through Chatbot, if user gives incorrect userID, bot says ''Incorrect answers provided. If you're unable to remember the answers please contact your Administrator or else Try Again!''. Here, user gives correct answer bot still bot says 'Sorry, I did not understand 'bottestpartner'. Please try again.' if again user gives correct answer, bot says 'Thanks. Have a nice day.'

Now, if try again is start again with 'Hi', then this needs to be communicated to user. Otherwise the user will be clue less. PFA screen shots.