This is just plain wrong. I'm sorry for you. I would submit new application, however, add an explanation letter adding screenshots of your existing application, adding information about your communication with MP and IRCC including the recommendation to reapply. Assuming that there are no errors in your initial application this is the error on the part of IRCC. I hope that they honor their professionalism and would prioritize your application.
You will have to sign all your documents again (with current dates as it's already 6 month old and can be considered expired). It would be better to get new PCC (or if you think that it will take a lot of time, at least add your old ones but request new ones as well and submit them as soon as you get them via webform, you can explain this in the letter as well)
And I would also contact MP for them to follow up your new submission with IRCC.