Purchasing tickets and engineering works

[Tomp94]

I am looking to purchase a day return ticket from Worthing to London Victoria on 16th Feb.
There is engineering works at Victoria meaning trains are diverting to London Bridge.
I am being charged the fare to London Bridge.
Why?

 

[Watershed]

The cheaper Super Off-Peak Day Return fare you are probably expecting to pay is specifically defined to London Victoria rather than London Terminals. Therefore when the itinerary is only to London Bridge, it isn't offered.

As per NRE, there is however ticket acceptance in place to allow London Victoria ticket holders to travel via London Bridge and the Underground. This only applies to paper ticket holders, since TfL refuse to apply this ticket acceptance to digital tickets (such as eTickets or smartcards).

You can either buy the Victoria fare at the ticket office or ticket machine on the day of travel, or specify something like "via Clapham Junction" to ensure you're offered the Victoria fare on an online journey a planner (e.g. see this link).

 

[Edvid]

Yes, according to BR Fares the £24 Super Off Peak Day Return (route Not Gatwick Exp) is issued specifically to Victoria; in comparison the Off Peak Day Return (route Any Permitted) to London Terminals costs £41.

Notwithstanding the OP's circumstances (which appear to have been solved), I see the £31.80 Travelcard equivalent is not route/destination-limited and therefore easier to generate without having to define the route in the journey planner.