You might’ve had grounds to sue (though I agree it would’ve been expensive and possibly not worth it). What they did is at very least possibly against principles of good faith and fair dealing, which could’ve been grounds for getting your money back (at least - you may have been able to recover damages for what you should’ve earned from using that space, too). The “bad faith” aspect would be knowingly renting you a space that you can neither use nor improve to be used. Contrary to what others are saying, just because something is in a contract, doesn’t make it enforceable. There are literally dozens of ways that this can be the case. Only a good lawyer can tell you for sure.

I don’t say this to pile on, I know others are telling you you could’ve sued, but rather just to be helpful if this ever happens again. And in case it’s happening to anyone reading.