The same thing happened with my application and I was ready to leave Canada as well. The person at the mail reception has put your application in the incorrect pile. the addresses for inland and outland are a different PO box but the office is the same so the person responsible for receiving the mail did not pay enough attention.
What I advise you to do (what I did and my application was approved in 3 months after they re-received it) is to write a letter stating that your application was incorrectly sent back to you as the form requested was for inland but you are applying outland. And as for this mistake you request a rush processing of your application. Also write an all the documents you can that yours is an OUTLAND application. that should enable the officer processing your application to be 100% sure that you want to apply inland. For example I had 60 pages of pictures and the story of our relationship and at the top of each page I wrote my name, UCI number (if you have one) and OUTLAND FAMILY SPONSORSHIP. I did not want to take any chances.
When you send it again you will need to wait the 56 waiting time but they might try to speed it up in the second part
I wish you luck