How TF can companies and recruiters do this? Is there anything I can do?

I was in the 5th stage (of 6) in an an interview process with a company that focuses on AP (Accounts Payable) process automation. I had been given a deck and asked to prepare a mock discovery call. This process entailed:

• Selecting a company with under 500 employees
• Finding a target ICP
• Building and sending interviewers a prospecting email
• Build a deck and talk track to effectively run the discovery call

Outside of that, understanding and asking questions that pertain to this particular "company's" processes as well as gaining a high-level understanding a fairly technical solution this company provides.

All together I put between 15-20 hours of time into this, only to be told 36 hours before the call, that they extended an offer to another candidate.

This was for an April 1st start date and I even clarified with the recruiter that decision wouldn't be made until all candidates completed their respective stages.

I am so taken aback, frustrated, and devastated at this given how much time I spent and didn't use that for finding other jobs.

Is anyone else experiencing this? Is there anything that can be done about this BS?