Horrific 20% increase

I am completely horrified by discovering a 20% increase in my premiums with values and benefit decreasing. There is no justification for this kind of increase, I have previously tried to call and ask to reduce the increase and all I get is 'sorry that's the increase amount'. I have also had major issues with contractors in the past where their workmanship is absolutely shocking to say the lease and when I try to complain, I can get hold of anyone to speak to or ok we will speak to the contractor. This is all just disgusting and shocking to say the least and needless to say we will be leaving Discovery