Rebuild a wall

The top row of concrete blocks which have a slatted fence attached (on both mine and my neighbours side of the wall) fell down and I’m hoping for the row to be rebuilt and where the wall is slanted (falling to one side) and may fall in the future to be secured. Pictures attached. Hoping that it won’t be a full rebuild and open to advice on the best way to rebuild and secure. Also open to offers as amount entered is the ideal max budget. Bin cover in picture is easily moved.