I'm not an expert in this and I've just picked the brains of one of my colleagues on this for you. Also there are a lot of unknowns such as who installed the kerb, what was it designed for, who has responsibility for maintaining the road/ footway, yaddda, yadda, yadda.......
We are assuming that the dropped kerb is in place for vehicle access to a drive and not for pedestrians/ pushchairs/ wheelchairs. If so and also assuming that the kerb has been like this for some time and that you haven't just installed it yourself then as I understand it the council should put back the kerb as it was with no charge! I'm also assuming that the length of kerbing doesn't need to be extended to facilitate access, etc.
But I would ask the council to justify why you need to pay for what you've already got!
Not sure if this helps, but it is worth a shot!! 