Hey Daizzy! So sorry to hear that. I believe you've come to the right place. Someone will give you guidance soon according to their experience.
The little that I know is not everyone gets called for an interview. However, everyone has to send a passport so that a permanent residency visa can be stamped on their passport regardless of the visa office.. what is your spouse going to travel to Canada once everything is approved? In the meantime, call CIC here in Canada and ask the procedures of you requesting for a change of visa office.
Hope this helps a bit. Hang on and someone should give you a concrete answer.
Good luck.