Expensive taxi insurance

Got a quote of €2700 for taxi insurance on 1 1.4cc in dec 08 from insurance, been with an insurance company on private insurance for 1 yr and 10 mths then with own damage claim in 07 and involved in another accident in 04/08 which th other driver accepted blaim and insurance company made full recovery; disclosed all these; paying by dd and initial deposit of €854.

car scratched neighbour's car late jan and initially called up ins. co. but was resolved between us then informed insurance co about this to cancel claim. Was adviced that claim will be cancelled; so no pay out.

Upgraded my car to a 7seater, 1.998cc in feb due to additions to the family and taxi purposes. wrang insurance co and premium was hiked up to €4800 with monthly dd of €485.Cannot aford this due to the state of the taxi biz after making a payment for 03/09. Called ins coy to cancel the policy with a few of getting some refund from about €1850 premium paid btw dec and now but was surprised to hear hat i cannot get any for the fact that i pay by dd and the claim notified though no pay out. Slammed with another bill of €453 for outstanding premium till 16/04 when i cancelled. Is this right and what shouli do as i cant afford this anymore. Shoul i not get some refund despite having paid more than a tird of the premiun in 3 months

if your paying by DD then you are essentially paying by the month.
Am I right in saying that your last payment was taken on the month before you cancelled and that the €453 is for the period of the month that you have not paid.(i.e the period between your last payment and the date you cancelled) -
If so then there wouldnt be a refund due as you have only paid for the proportion of the year that you have been on cover and the €453 is what is known as a time on risk charge for the period of time you were on cover that hadn't been paid for.
The claim would only have an affect on your policy if the company were at a loss as a result.