Instalment

My instalment on my policy was R1580 on my two vehicles and for my home contents. Now in the beginning of this month my instalment went up to R2700,the reason they say is because they did a annual review on my policy and that is the reason. On my side nothing has changed on my policy with my personal information and I did not claim for anything, according to them there is a few factors in the industry like price increase on parts. Price increase in the industry goes up by more or less 10%, in my case my instalment went up by more than 50%. IS THIS POSSIBLE? On my Pajero Sport my instalment went up from R644 to R1300, not possible. I am very disappointed with them.