Burgess Group SQL Developer interview questions

After a phone screening, they send me an assessment. It was about some high level SQL query. I solved it all. I sent it back and after 2 day they invite my for an interview. They were impressed by my skills and experience. But after 2 day they sent me a letter which mentioned "We can not offer you any full time job". What surprised me is that I had about 5 vendors email after a few weeks which was related to this job as contractor!