If you've left critical medication or something like that on the train then by all means contact a member of staff or a police officer and it will be dealt with as a matter of urgency, I'm sure (even if you contact customer relations it will be progressed urgently I'd have said).
No passenger carries critical medication. They demand a taxi after their train has been delayed ten minutes. One passenger found it wasn't so urgent when due to a road closure there was a lengthy diversion which meant they would arrive after the time they said they MUST have their medication so I offered a taxi to the local hospital.
leaving at Crewe.