I'm sorry to be the one to tell you this, but I highly doubt you'll get your visa tomorrow. I think it would probably take longer than one day to send the passport back to you, much less get it fully processed.
This is why you're told not to book travel before you have your visa in hand, and to allow lots of time for visa processing. The average processing time is not a processing standard - it's an average of how long it took most applications to be processed. You should not use that as an indicator of when to submit your application.
You'll want to see how you can get a refund on your travel arrangements.