Horrible service

I recently called in to change my debit order date, and i was told that for that to happen, I need to pay double the premium because when they loaded my policy it was done in arrears. i told the consultant that i wont that extra money this month ( even though it was not my fault that They captured incorrect start date). I aske can we negotiate to pay the extra amount the following month, they refused and very to cancel my Policy. So this means that, had anything happened to me i was not going get a payment out because my policy is in arrears ( even though i have never missed a premium. i was will to pay the extra but Finances are tight this month. i think this is unfair.