Short Term Exorbitant Premium Increases

I received an increase letter effective Dec 2015 about a 30% increase. Received another increase letter effective May 2016 about another 30%. So in total over a 60 % increase in premium in less than 6 months. I think this is totally unreasonable. I had a vehicle claim in 2014. Motor portion has increased by 100% but non-motor with no claims increased by 40%. Furthermore I enquired about the recovery progress wrt my vehicle claim - seems like a shambles, should be an open and shut case really - apparently they can't get hold of the other driver! I've now informed them that this is company car so really cannot be that difficult to get finalisation.