Chamartin is a large station serving the North West of Spain. When I visited Madrid a few years ago I stayed in a city centre hotel and got the train from Chamartin to Bilbao. It’s very quick to get to by metro from the city centre.

I tried to de-activate my account earlier using an ipad and got the same error message. I then read that others had experienced the same problem and they suggested using my phone - worked first time, so cheerio Mr Musk!