I know that this is confusing and doesn't seem to make sense, but to get down to the nitty gritty of the matter the sensible option is for you to look at your insurance policy and find the address of their Complaints Department which must be included in the documentation. Write to them complaining that you appear to have been overcharged either for this renewal and/or for the previous 3 years. Under the FSA regulations, they are obliged to give you at least an acknowledgement within 5 working days and thoroughly investigate the matter. Although this may drag on for some time, they have to keep you informed every 4 weeks until the situation is resolved. After they have sent their final answer to your problem, they will also include details of how to approach the Financial Ombudsman Service, which you can then approach to adjudicate should you not agree with the insurers response.