Topcoder interview questions

Initially I thought the interview process went well, I had a preliminary interview and then a follow up with the director. After interviewing I was literally, I mean literally offered the position. I have the email they sent with the job description and congrats. They even called that Friday to tell me I got the job so I could have a "happy" weekend. I was told that HR would reach out the following week with my offical offer letter. I didn't get that email, so I contacted the woman who offered me the job midweek only to be told the position wasnt available. They instead offered me a 15 hour a week part-time contract. I was in complete disbelief. Topcoder's HR and management put me and my family in a terrible predicament. I turned down a previous job offer at a higher paying company because I really liked the team. Please be weary of this company and their negligent hiring practices.