Just read up on this from a few view points, the consensus is there is no easy or cheap fix.
1, A company will quote for re applying a render or similar as the brickwork will likely be in not state to be left as it or just painted on.
2, rendering over it still requires removal of the original dashing, going over it is considered very bad workmanship and will lead to repairs in the future being needed and likely more costly.
If the whole house is pebble dashed the experts seem to say accept it or get another house, i assume this is because the cost to get rid would be to high possibly.