Has the actual itinerary booked been posted? I can't spot it but may have missed it.
Unfortunately I'm not sure there's much more anyone can say to help without that information. I note that the thread title refers to a platform being changed, but again, without knowing which services exactly the customer was booked on it's difficult to guess if something actually changed.
If the customer was on the correct platform for their booked service but this then changed, it's a different situation to whether they were on the wrong train just because.
Unfortunately I'm not sure there's much more anyone can say to help without that information. I note that the thread title refers to a platform being changed, but again, without knowing which services exactly the customer was booked on it's difficult to guess if something actually changed.
If the customer was on the correct platform for their booked service but this then changed, it's a different situation to whether they were on the wrong train just because.