FIND/HIRE A LAWYER ASAP!! You definitely have grounds for this case. If you think it may be too expensive, I suggest using Lawdingo (https://www.lawdingo.com/lawyers) as you can cold-message/chat with lawyers for free. I am positive that if everything you have presented is true, someone or another will be more than willing to represent you and help you take the appropriate action.

Really sorry to hear about this but best of luck, its unfortunate this happens with such large companies. Nonetheless, hope it gets resolved soon--good luck!