I was invited to a second interview with their CEO at their office. It went well, he offered me the job and I said I was willing to accept. I discussed the details and the contract with their HR officer later and I left believing I was offered a new job. My surprise came later when I haven't heard back from them for few days. I contacted their HR, who replied after 2 days he left the company, but he believes the CEO will search for other candidates. In my whole work experience that was the most unprofessional and disrespectful behaviour I have met.