So by mistake you did the following:
1. Entered it incorrectly
2. Picked it incorrectly
3. Registered the pick incorrectly
4. Confirmed it onto the shipment incorrectly.
There are four steps in this process that you physically undertake and after getting it wrong on the fourth you have to receive and reverse. Whilst it would be nice to have an undo it is not there, so if you want it you have two choices - manually process it thorough or customize and build in an undo. However you should review your business processes as well.