Definitely. That alone is grounds to have the speed humps removed.
The fact that cracks have appeared in your wall is evidence of the tremors sent though the ground by vehicles mounting and crashing back down off the humps. It is patently obvious to any structural engineer (and to all but an idiot) of the damage these obstructions cause to the sub-structure of the road as well as to the vehicles passing over them. One of the most crass stupidities of the previous government was to subvert funds from repairing roads to installing speed humps, speed cushions and other impediments on roads. Yet large amounts of taxpayer’s money were allocated to this folly. I even receive e-mails from the elderly (that these things are supposed to protect) complaining of having tripped over them and broken limbs.
Hit the council with an estimate for demolishing and completely
re-building your wall with deeper foundations and I think you'll soon see the end of this pestilence in the Queen's highway.