Ugh, I feel for you. I'm done with the process now, but I had my app returned multiple times, and in one of the incidences, I realized my mistake three hours after mailing the app. Then had to wait weeks just knowing it would be returned to me. So awful. Hang in there... even if you can't get it back, a couple months extra delay in this process are honestly to be expected here or there. Hopefully you get speedy processing once it's all said and done.
Unfortunately calling IRCC and trying to submit replacement documents has about a 0% chance of succeeding (speaking from experience). They are very strict on returning applications and will make no special concessions to help you replace documents that are incorrect.