Hello Lloikuejoitt74
I am sorry to hear about the troubles your mum has encountered. Sure, we can help you.
You can use the complaints form for that purpose:
→ Claims and complaints. | SBB
When filling in the form, on step 3, you will have the possibility to upload any proofs such as the ticket and the taxi receipt.
Clicking the link above (bold text), I have already preselected the reason for you; all you need to do is adding the train information and the contact information, plus uploading the documents. Then send.
The processing may take a few days as there will be many requests for compensation.
Kind regards,
Roland