Denied means you can't build it, so you "disassemble it". "You do it -so you can save the materials & this time "Apply for a Permit & wait" If they deny you, you can find out "WHY" and make the necessary modifications to your plans to be acceptable by the city so you can build some version of your plan...so all is not lost. At least you have the materials, not a pile of splinters.
Otherwise the city boys will come out and TEAR IT DOWN. It does not belong there so city does not need the materials so it is broken up as junk. It will be loaded into a dump truck and hauled to the dump. You are paying city workers their wages plus the cost of the equipment(dump truck & backhoe)use and it comes out of your city taxes if not directly out of your wallet. So a lot of associated costs (dumping fees, use of truck, truck driver, back hoe and back hoe operator and you are not compensated for anything.
YOU DON'T FAWK WITH THE CITY (does not matter if you a home owner or big time contractor; both fall under the same rules and penalties.
My contractor did more demolition than he had stated on his permit...it cost him 6 months of STOP WORK on the project...as city inspectors just happened to drive around to check out projects to check for compliance violations. (many contractors are just hoping they don't get caught, so are gambling.) The owners of the residence were kept out for that much longer.
On a different job, because the builder did not apply for a permit. They tore the completed house down. City workers do not mess around.
By all means, go out and hire a Lawyer. You will have to pay his wages too, because he can NOT do anything. But he will charge you for that.