The Dulwich Estate Scheme of Management officers are well aware of the situation concerning the retaining walls on Sydenham Rise. To the best of my knowledge, the work is currently out to tender and freeholders are waiting to be informed by the Managers on the result.....it is rather more complicated than 'Dulwich Estate = wealthy, therefore spend money quickly on repairs' .....i wish....!
Freeholders are liable for a lot of the cost of repair and maintenance works on amenity areas.

Too long and convoluted to go into here, but: http://www.dulwichestate.co.uk/som/

The restrictive covenant (administered by the Scheme of Management) on properties on the Dulwich Estate operates in the same way as Hampstead Garden Suburb, Bournville and Poundbury..... i can't comment on how quickly repair work gets done in any of those places.

Anyhow, all agree that 'the walls' are a matter of urgency, especially as the winter seems to have had a dramatic effect in hastening the decay, so maybe your letter will have chivvied them along a bit.....