Hi. I'm looking for a train from ely to cambridge, if there is one.
Okay, what day do you want to leave?
I would like to leave on Sunday.
How about TR9382?
Well I need to leave after 14:45, so if it is after that time that'll work. 
TR9823 will leave at 15:35, how does that sound?
I think that'll work.  I need to reserve two seats, can you help me with that?
Booking was successful, the total fee is 7.04 GBP payable at the station. Reference number is : 6NJA0V8R.
Thank you. That's all I need for now!
You're very welcome. Have a great day.