In message , Robin Mayes
writes

Apparently you can use your Customer Charter vouchers to add credit to
Oystercards.

Prestige told me the same thing.
In answer to my questions they also said there are no plans to have
Customer Charter credits automatically added to your Pre Pay; it will
still have to be applied for in the same way after a delayed journey.
Also, there are no plans to change the way in which Customer Charter
refunds are calculated.
--
Kat Me, Ambivalent? Well, yes and no.