Aha! that might be it Roger. We started our service with Orange c2009 and carried over the contract when we moved to our new build in the same commune some 7 years later.
In our case we started with a broadband /phone service in 2010. After suffering poor internet speeds for years, we cancelled the contract in 2018 and went fully ‘4g’ with Bouygue.
We were charged €50 by Orange as a cancellation charge, but consoled ourselves that we got a ‘payback’, through the change, in 3 months.
Just remember that if you live out in the sticks, keep an old school physical landline and a corded handset.
Wide area power cut = no cordless phones and very limited mobile phone connectivity as rural cellular network sites have little or no battery back up.