Congrats! Isn't it ironic when that kind of thing happens? You put your heart and soul and grammar instincts into one piece of writing, only to have something else you wrote (which you hold in much less regard) to get the credit?
It was my first contest too but I submitted it 1 day too late (thought we had until the end of August) . But I am so grateful to have even tried for it because it was incredibly therapeutic and it led to a job offer through IG :D