Judging by other practices I've seen in France, I'd say it's legal, but they have to notify you. That means "let you know", not ask for confirmation. I've had

Judging by other practices I've seen in France, I'd say it's legal, but they have to notify you. That means "let you know", not ask for confirmation. I've had several times get my mobile phone or internet subscriptions "improved" with some useless extra, like more GB (I barely use what I have) or more TV channels (I don't even own a tv) for the low price or 2-3 €, which is like a 20% increase. They usually take the form of a "free" add-on for three months, and then you have to pay. They typically message you, and you may cancel that option. But if you don't pay attention, you'll have to pay for it.