I am sorry for the delay. The site was down, at least for me, for a while.
The contract would normally be considered to be firm and you could be sued to compel you to adhere to its terms.
But what you are saying is that you were mis-represented in terms of what you were getting as you didn't understand that it was a rebuild. If that is the case then if this went to court you could take the position that you are not getting what you were told you were paying for and so the dealer breached the contract thus rendering it void and you want the deposit back.
So what you do first is go to them tell them your position.
If that doesn't work you go to head office for the dealership.
If that doesn't work you can file a complaint with AMVIC:
And you can file a complaint with the Consumer Protection Branch:
If none of that works you can sue them in Small Claims Court and can self-represent so long as the value of the car is not more than $25,000.
If it gets that far you can always post on this site again and I can assist you as you go through the process if you find you need some help from time to time.
If the car is worth more than $25,000 you will need to sue in superior court and if that is the case it would make sense to retain a lawyer to threaten a lawsuit.
Does that answer your question?