I did not add this payment my son did this and I do not wish to have Apple TV so how do I stop payment

Follow the steps in the support document you posted from. Specifically the one that states "if the charge is for a subscription you no longer want, you can cancel the subscription".

Blue text is a link both above and in the support document.

Then make sure you setup Ask To Buy, to prevent children from simply buying or subscribing to things without authorization