I have had a response from the council, and they have indeed concluded that the speed hump is too high! 

"James has surveyed the road hump and concluded that it is not constructed in accordance with our standard detail (slightly high in places). James has also met with our contractor to discuss remedial works."

They've asked me again to drive over the hump and demonstrate the issue so that they can review, but I have declined to drive over it and damage the car again (insert image of Bart Simpson reaching for an electrified cupcake). Especially as to repair my vehicle, I have to revisit the manufacturers in Wednesbury, Birmingham.  I also know that from going over those in Chipping Norton and Charlbury that the 'standard' humps are effective at reducing speed and that I am able to traverse those without grounding.

I'm very pleased that we are getting closer to this being resolved and thank everyone for signing.