Southern did a trial on the key of a carnet like option between horsham and victoria, but never followed it up. I'd really appreciate the key to support carnet like tickets, and be useable on london overground.
Southern also used to give significant discounts of 10% to 15% for buying tickets from them online on their website and picking them up from the ticket machines and they did this even before they had any ticket machines on the ground at Holmwood, Ockley or Warnham (forcing one to travel with no ticket, or possibly a Permit To Travel but originally we didn't even have those, and then ask to be let through the barriers at Victoria to collect the ticket from the concourse machines as it didn't seem possible to do this at the Excess Fare window). Now they give no such discounts at all for online pre-purchase and they have pushed fares up south of Dorking way ahead of the rate of inflation.
As with Zone 6 running out at Ewell East and no Zones 7 to 9 one has to conclude that GoVia Southern think we have no choice (no long distance underground does not exist out here in the deep south and runs out at Morden and Wimbledon) and so they can exploit us for any extortionate fare they like. Peak hour fares are absolutely hideous south of Dorking but the Super Off Peak return ticket from Holmwood and Ockley doesn't cost any more than an Off Peak return ticket from Dorking, although you have to catch a somewhat later train than with an Off Peak fare.
I also find it particularly outrageous that most of their MeetTheManager sessions are held at London Terminuses in the morning peak (when I never use their services at this time of day because they are so hideously expensive) and they don't email customers to remind them of the occasional upcoming session (like only once or twice a year) at London terminuses in the evening or very occasional ones held at stations outside London. So one normally learns that these affordable to reach MeetTheManager sessions have taken place only in arrears.....................
I see that Wookiee also commented on the Southern Carnet trial and what had happened to it back in April 2017 at
https://www.railforums.co.uk/threads/whatever-happened-to-the-southern-carnet-ticket.144921/
I also used to belong to their strange passenger forum that took questions and gave answers lives for a couple of hours every three months and was then frozen with no chance to continue the discussion further. But that now also seems to have died a death as far as I know.
Basically Southern management clearly feels we are easily ripped off down here and doesn't like being held accountable by having to meet us too often to explain these decisions. They haven't yet given any Meet The Manager sessions for 2020 at
https://www.southernrailway.com/help-and-support/listening-to-you/meet-the-manager