Royal Bank of Scotland

I used to work at Birmingham City University. I was Unfairly dismissed,now have an unfair dismissal + Racial discrimination case against them wit ACAS/employment tribunal. During 1 of the investigation meetings, I was waiting for the bus as usual and there was an idiot that went past and shouted P @k1 at me whilst he was riding past on his bike. I checked my notes and there was this good Samaritan waiting at the bus stop with me and he witnessed it. He said he worked at the RBS branch in customer service at Broad Street. I wanted him to list him as a witness in the employment tribunal case but I asked RBS they were unhelpful, did not provide any further details. They now don't want to get involved as they have clearly have been exposed. Their employee usually catches the bus at 8.15am because when I worked at University college Birmingham he was there regularly but when I worked at BCU the meeting was at 11am and UCU told me to come in earlier. And he's there telling me has a meeting?