Lymphoma Research Foundation interview questions

After applying for the position online, a phone interview was scheduled with the Special Events Manager. Three weeks later, we set up an in person interview, followed by another interview with Director of Special Events & the CEO. A couple of days later (on a Fri), I was offered the position and happily accepted. I negotiated the salary, and was told someone would call me back ASAP. Monday afternoon the job offer was rescinded. I was not given an explanation other than "we've had an internal issue come up and can no longer move forward with the position". I was lucky to not have already given my notice to my current employer. I was appalled when one month later the same job specs were posted under a different position title. LRF's staff and directors are unprofessional and unethical.