Based on last year’s premium being £360, I suspect you are one of those who have been loyal to your insurance company, renewing year after year – as a reward for your loyalty you have been shafted by them.
If your renewal is due, you could log on to your insurer’s website and see how much your premium would be as a new customer – you might find they offer a competitive quote.
For many years, I insured my car with Directline; each year (after receiving my renewal notice) I would ring them and advise that I did not want to renew the policy – when asked why, I would tell them that I had renewed the insurance (under the same terms) for a cheaper price with Directline.
There is some new law that is supposed to stop Directline doing what it was doing (offering cheaper insurance to new customers); if that law is successful, my premiums will have to increase since you (as a loyal customer) will no longer be subsidising me (who shops around).