Unreasonable increase, no PV, cancellation ignored

Amsure steeply raised my insurance premium by over 21% in February. They sent me the documentation and I got in touch with them, telling them that this is unacceptable. There was no reason; I had not claimed, there had been no accident; they cited \inflation\" (official CPI = 7%). But the value of my car is actually getting LESS not more, every year as the car ages. So they will be paying out less, not more. When I asked, they quoted \"parts\" at me. This is patent nonsense for older cars as insurances either cover themselves with high excesses on repairs or write the entire car off. I did not agree to the increase and sent an email earlier this month cancelling my policy