Refund Refusal

Imas has been debiting insurance on my vehicle now that i have cancelled and had requested a refund way in advance after they had debited for the month i was advised that apparently i was a month behind. told them this is not possible so if i had an accident at the time would i have been told this in which how could i be a month behind when they debit monthly directly from my employer . I've sent loads of emails no response