That may be but it is on CBS and they are ultimately responsible for what is seen on their network. They likely had final approval of the halftime show.
It would be more effective to contact the advertisers.
Why would anyone in their right mind want to write them. They will just ignore it and/or pass the buck.
However, if you saw it, or your children saw it and you were clearly offended by it, then I would suggest you initiate legal action.
This was no accident, it was very cleverly staged. (I believe the word Im thinking of is "deception".)
The network operates under guidelines and so do the artists. I see it in the same way that a food manufacturer packages food and has deceived you as to what the ingredients are.
Someone is liable.