Assessment centre Written Test Interview Presentation

I saw them at a university fair, asked if they are able to sponsor for tier 2 visa, they said yes. I applied online (deadline: 1st April). I got an email 2 weeks later inviting me to an assessment, they gave 4 dates to choose from (the process would take a month). On the email they explained the assessment process, a writing exercise, a presentation followed by an interview. The assessment was in a hotel in Central London, the interview went well, they are very friendly and make you feel comfortable. 2 days after the last interview date they called me to say unfortunately the Graduate Training Scheme is unable to act as a sponsor for visas, although they gave me the information at the fair and also during the process they kept asking about the visa requirements. They also said the official email should come soon but the email only arrived almost a month later. They never gave feedback about the interview.