Hello. I need advise regarding a slip in my local supermarket, I slipped on a poster that had fallen off the wall and cracked my knee. It was one of those posters that advertise the cafe I think. I filled in an accident report but have heard nothing from the shop since and this happened months ago and i'm not happy with them at all. When I ring they just fob me off so I want to take it further. how do i begin please??