SNCF can book this reservation (did you call +33 1 84 94 3635?). CFL should be able too, by the way (ticket office or by phone). I think you talked to an inexperienced person, unfortunately. You can also call Belgian railways.
A reservation can also be booked via Interrail (+ 2€ booking fee) and there you can also see availability for your travel date.
Hello thank you so much for your feedback!
I will check again tomorrow with CFL or sncf.
However the Belgian number did not work today.. Maybe tomorrow.
Finally the link you sent me for the interrrail page is not working. I get an error message. Any further guidance?
I've just noticed there's a general problem with the Interrail website. Even the homepage is not showing anymore.
Thank you for the replies looking forward to book everything
Have a great day
So I got updates from a kindly person at the CFL hotline (thabk you for the tip @rvdborgt ).
She told me that they can TGV tickets via phone or inside (in Luxembourg at least). Réservation via phone takes 5eur fees. BUT for the trip in TGV between Bruxelles and Marseilles on the weekend I wanted to travel TGV did not have places left (while I was one month in advance) so bevare!
I will check if I can refund my pass as I gave to pay an extra ticket for this trip that costs more than 100 eur…
PS. :for those that cross or go to Luxembourg by train:check out the latest rail works in April and May!
Have a great trip
She told me that they can TGV tickets via phone or inside (in Luxembourg at least). Réservation via phone takes 5eur fees. BUT for the trip in TGV between Bruxelles and Marseilles on the weekend I wanted to travel TGV did not have places left (while I was one month in advance) so bevare!
These TGVs from Brussels fill up quite quickly, especially in the weekends and around holidays.
If you say on which date you'd like to make which total journey, maybe people can suggest alternatives.
Ok good to know for next time that Tickets could be switched. For now I have booked separately a ticket for the whole trip.
Thank you for the replies!!