Your policy document or summary should contain a section along the following lines:
"Cancellation
Your right to cancel
If you are dissatisfied with the terms and conditions of your contract, you have the right to cancel your policy back to the original start date. If you decide to cancel your policy in this way, it must be done within the 14 day cooling off period. The 14 day cooling off period commences when the policy is purchased by you. Cancelling your policy in this way will mean that you will not have been covered by us. If your policy is cancelled back to the start date, we will return the premium paid minus an administration fee (which will be imposed by us), provided that no claims or accidents have occurred.
If you do not exercise your right to cancel within the 14 day cooling off period and provided no claims or accidents have occurred, you will be entitled to a refund of the premium paid, subject to a deduction for the time for which you have been covered. This will be calculated on a pro-rata basis for the period you have received cover. There will also be a cancellation fee.
If you exercise your right to cancel outside of the 14 day cooling off period and a claim has occurred, you will not be entitled to a refund of the premium paid and we reserve the right to apply our cancellation fee.
If you have not paid us sufficient money for us to retain premium, or if you have not paid the full annual premium but have had an accident or claim or committed a fraud or made a false declaration, then we reserve the right to recover the money that you owe and apply our cancellation fee."
In particular take note of paragraphs 3 and 4. You are not entitled to any refund as you have made a claim and you owe the insurers the full years premium.