Shocking Price Increase with NO Warning

How does your premium go from R557.28 to R922.05 with no amendments on my side? I have been with First For Woman for 5+ years and have not once claimed, but they merely increase my premium without my knowledge and say they sent through a correspondence with I did not receive!! I then get shocking feedback about how certain parts of the vehicle has increased which they think justifies such a huge increase in my premium. Then when I complain they drop it to R733.79 how is this even possible??, from R557.28 to R922.05 then when I moan about it they give me the same cover for R733.79 - I am not happy at all!!