Radiant Exhibits interview questions

I received a call at around 8:30 in the evening and I was called in for a face to face interview which went really well. I was asked to ahow my skills in using MS Excel which I outperformed. Then I was told to wait for further information. After 1 week, I again got a call at 8 PM that I was being considered for the final pool of candidates and I will have to come again for an interview. I appeared for the second interview which again went as expected and I was told to come for a day at work( I was told that I will be paid for that day) to understand the company's operations. I was happy as I believed that I will get to know about the company's operations before I join. After working like a labourer for one entire day, I was told to wait for their final reply. They kept me waiting even after my follow up mails and after 3 weeks they send me a mail that the position has been closed. No mails after that. They made me work as a general labour for one whole day(the position I got interviewed for was the project manager's role) and didn't pay me a penny for my work. Also that position was not even close to project management but general clerk. It felt like they wanted some free labor for a day and staged interviews for that.