Well I find some of the replies very one-sided. I feel for the OP.
It is very definitely an IT issue and just bad programming that the website doesn’t pick up from cookies or prompt the user to state their country and language options in a way that they can easily set them.
To give another example where the IT is bad, perhaps the programmer thought they were being clever but just try booking an IHG hotel when in France or Germany and see if you can find what name they give for the UK when you try to change the country and language settings. And that is having previously set UK/English as your defaults on that same website.
Examples of good programming have the website say something like ‘it looks like you are in France would you like to continue in English or switch to French’ but defaulting to the language of the users device.
And no, it is not the browsers fault either.