Gave interview in Dec 2020, got confirmation of jo...

Gave interview in Dec 2020, got confirmation of job after 2 week. But after that no information. Waited till Feb. Suddenly got a call to join within 2 days & also confirmation mail. But on the day of joining no information. Called the HR she said no confirmation mail has came from client company. Waiting till now ,called HR after 2 days she told no confirmation of the job she will try for any other company.. Theyy make fun of candidate's time and expectations. Worst experience. Got another call from an another HR talking about the same job opportunity. I don't know what to say them