Newsflash: Deposit return request denied after developers didn’t fulfill promise

I payed a down payment 3 years ago for an apartment unit that was being built, i was told it was a one bedroom and one den. It is now done being built and they said due to city laws they were only able to make it a studio. That’s not what I agreed to pay for and I requested to get my deposit back, however they have declined to give it to us and offered us max only half the deposit amount. My real estate agent has not taken accountability for what I assume would be his mistake, as he was paid and it’s his job to make sure these things don’t happen. He was willing to only pay half for the cost of a lawyer. The lawyer is sure that we will win the case and get my deposit back but after the cost of having to pay the lawyer and rent a new place out I feel as tho I should get more than just my deposit. What should I do? Do I move forward with suing the developers? Do I go after the real estate company? Has anyone else been in this situation?