Dramatic increase in Premium

I had a shock when, I seen that my premium for Life Cover increased by nearly 35% . I went into the Cresta branch to enquire why , instead of the normal 9% in increase so dramatically. I also called the call center and the lady was not very helpful. Cresta branch advices me that they will call on the day, which was Tuesday. I called Wednesday, I was told again we will call you later. Waiting for a call so long is unacceptable service.I was also told that enable to pay what I paid a month ago the cover I have on the cover I have on Policy will be reduced. I have this policy for 12 years and , I am seriously thinking to go to another Insurance Company .