182 Duchess- dormer reno- threatened with “substantial fine”

Our growing little family is going to court this Monday 19th November 2018. London Ontario City are charging us with a substantial fine because we had to build the dormer slightly larger than the original heritage approved plans due to meeting building code. The City signed off the work completed, allowing us to proceed, and are now back tracking, having admitted their mistake.
The adaptation was made by the contractor without consulting us, the home owners.
We are looking for signatures from supporting people for the City to drop these charges.
Thank you for your support.
From Alistair, Beth, Sam and fetus Dorward