I just called CIC now and they told me that I should be getting my test invitation within one month maximum . And the lady told me that she is sure of what she is sayingMany people have the same situation with Mississauga office, the only thing we can do is wait and accept the reality that the process won't be done within 12 months. The sooner you accept it the less anxiety you will feel.
Or there's also the alternative: go back in time to Oct 11, 2017, and submit your application from some place outside GTA - but that would need a time-machine