I find this reply quite offensive, Wavetree is a Station in Liverpool so could easily be misunderstood not just by visitors to City but also locals not used to using the system.
It's railwayspeak and has been in use since, well, a long time ago.
It's a useful feature for those that know about it and understand it, as it enables travel to any station within that group, opening up journey possibilities.
London Stations, Birmingham Stations, Liverpool Stations all exist as groups.
When someone arrives from London Euston, they can use their Liverpool Stations ticket to get, for example, to James Street. Very handy.
Unfortunately, I don't really see too much of a way around this in terms of catering for people who don't know about this and who may make a mistake, but it's rare to hear anyone make the mistake mentioned, so perhaps any change would be a sledgehammer to crack a nut.
The ticket was purchased from Hunts Cross, another part of the same city. I think there is only so much leeway you can give people, and someone in Liverpool not having awareness of how their own transportation system works I think is not going to get much sympathy from anyone, least of all the TOC, I'm afraid.
FYI, if it's offpeak travel, a Saveaway is just over £5 and enables all day travel throughout Liverpool, and for onpeak travel there are some good value zone tickets available from your PTE Merseytravel.
http://www.merseytravel.gov.uk/Pages/Welcome.aspx
Your city is lucky to have such excellent and comprehensive transportation, in a country that typically does not do these things very well, so after you've gotten over ponying up the penalty given (and please do just pay it, because if it goes to court you'll only end up paying more - by all means
after settling the matter complain to the TOC about the fact the ticket he had cost more than the one he should have had), I'd recommend getting to know what's on offer.
In the Liverpool case, perhaps they could be "Liverpool Terminals"? cf London Terminals?
Yes that's not a bad idea. I think as well they could do with having a One Day Travelcard option, which would then cover such journeys for people coming into the city (note though that this is already available for the OP, as the ticket was from Hunts Cross within the PTE area).