Hello shiji
Kindly contact the SBB Contact Center team by calling +41 51 225 78 00 (hold the line until someone answers), or drop them a message using this form: Claims and complaints | SBB help & contact → Choose the subject A ticket / travelcard / product.
Attach the concerned ticket and explain to them, what needs to be altered.
Please let us know if we can assist you any further.
Best regards,
Roland