Thanks Dominique.
Well so far, sending the operators an email similar to the content of my post has been sufficient and we have not been asked again to add an entire terms list.
I think that the fact that we add their trademark name (as in one word xxxxbingo, xxxxbingo.com) as a negative keyword is regarded as a good will gesture and they tend to be satisified.
Nevertheless, we wouldn’t hesitate to go to court if our program were stopped on this basis and I would be happy to post the progress on this forum.