Those are standard terms with the UK Brand casinos. The T&C’s nearly always state that you can’t compete on certain terms or use their Brand name in PPC ads.
As devil’s advocate here, there is some logic in that when you think about it and if I ran a casino I’d probably state the same. It’s counter productve to the bottom line to have your affiliates pushing up your advertising costs and I think many people would be surprised if they could see the costs in running an online casino. I’m always seeing people say “oh it must be really cheap”, but I’ve seen some figures and frankly, I was quite amazed.