Hello Thuxoule71
I see. Someone might have abused your personal data …
You should contact your “Assurance protection juridique”, if you have one, to assist you in this matter
(btw, are you French speaking, it would be a lot easier for me to explain it in French as there are so many legal terms, for which I have a hard time finding the English translation…)
You also have to contact Office des poursuites du district de l’Ouest lausannois by a consigned letter (Lettre recommandée), and tell them that you make an “opposition à la poursuite”. In this case, SBB has to prove that you were indeed the person travelling.
You can find the information on this website: https://www.vd.ch/economie/poursuites-et-faillites/procedure-de-poursuite-ordinaire/vous-etes-poursuivi-debiteur , see: “Si la créance est contestée”
I find it important that you ask for help from either your insurance or from a lawyer. Contact the Office des poursuites du district de l’Ouest lausannois to discuss the next steps.
This is all I can say / advise regarding this matter.
Kind regards,
Roland