>It is like saying that there is no free market in the sale of carrot, because as soon as I enter a shop that sells carrot and start to buy some the other shops have no ability to sell some to me at the same time.
You are very indignantly failing to understand that there is more than one market in play here.
Some user, Joe Smith, subscribes to Orange as an ISP. That user may have other choices; Orange may have competitors. That is not the market I am referring to.
Once Joe Smith and however many thousand others like him subscribe to Orange, Orange has a monopoly on those customers. If you are a content distributor, it is not possible for you to send packets to any of those customers without going through Orange. You must, at some point, connect to their network in order to reach those customers. Other than government regulation, nothing stops them from charging monopoly rents for anyone to make such a connection.
The content distributor has no control over what decisions end customers make in choosing between ISPs. Their choice or lack thereof is completely irrelevant since the content distributor has little if any ability to influence it: Maybe if you're YouTube you could cause an ISP to lose sufficiently many customers through having slow or no access to YouTube, but probably not even then since if YouTube's competitors are still fast customers are more likely to blame YouTube than Orange, and if you are the little YouTube competitor then it's totally hopeless because Orange can just cut you off if you don't pay whatever they ask and the large majority of their customers won't even notice.
Internet service is not a carrot. If you need a bunch of carrots you can still get all of them in one place and if that store mistreats you in any way you can choose from multiple alternative suppliers. If you need to reach the entire general public, each and every ISP can hold you up for access to their subset of the customers, because you don't need 100 carrots, you need 1/100th of every carrot in the world. There is no way for you to go to Free and negotiate with them for access to Orange's customer base. It doesn't do you a lick of good to get twice as much bandwidth to Free's customers if your problem is not enough bandwidth to Orange's customers. You have to negotiate directly or indirectly with Orange, who can hold up all comers.