ahhh that explains it then.
As a separate issue, curious though about the GB IBAN - has your Revolut account not been moved to Lithuania (so LT IBAN)? If not, presumably Revolut think you are still resident in the UK (are you?)
Sadly, despite EU legislation to the contrary, France seems not to respect the rules on IBAN discrimination.
Have you checked your Revolut account to see if the transaction has gone through? You may need to contact Revolut through support in the app to get the transaction nullified and then set up a French bank account (which you will probably need to have anyway to pay French utilities, tax etc) and start the order process over.
We have in the past managed to speak to a Bouygues sales person in English but it’s not encouraged. They found a English speaker who agreed to telephone our friend back to answer their questions but we had to request that first in French with them.