I think getting craft beer at Oxegen would be blood from a stone kind of effort. I worked at a local festival back in the old country and because it was sponsored by Guinness we weren't allowed to serve Heineken... (the tap was even taken off)
Witnness was sponsored by Guinness and the name changed to Oxegen when sponsored by Heineken, they're even naming the festivals to sound a bit like their brands! Evil... Maybe... Paranoid... Maybe...