IMHO, If I was in your situation and had to pay big money to ship it back, I'd look into getting a new knife and plate or repairing what I have.
Mine was pretty sharp out of the box, had to be careful not to cut myself. As far as the method above, if the blade was fairly flat against the plate, I'd try it, ......but if you can actually rock it side to side, your going to be there for quite some time trying to get everything flat again.....I'd return it or buy a new knife.
On a side note...I did a second batch this weekend , this time damn near freezing the meat, ground it through 3/8" plate and the texture was much better. Oh..and dint try to send left over casing down garbage disposer, I learned the hard way and spent an hour pulling it apart and unwrapping the casing from inside of it.