Compare and contrast that with FGW▸ /GWR▸ and their massive fare rises on the Cotswold Line, done by manipulating validities.
They did much the same on certain
SWML▸ services by manipulating advance fare availability - I think it had something to do with the change in government funding also, but nonetheless the end result to the innocent passenger was a huge increase in fares, particularly on the first 2 or 3 services after the peak is over.