Car Insurance - Changes to policy

[humpy07]

My MIL has recently changed her car, and telephoned the Post Office this morning to amend her insurance policy. She has changed from a Group 10 car to a Group 4.

She is happy to stay with the PO but obviously she expected the new policy to be cheaper than the old. In fact, they told her that the monthly payment would be more! When she asked about cancelling the policy, they told her that it would cost £340 to cancel.

I have since done an on-line quote for her on the PO website, and it comes out much cheaper.

Can they do this? I have told her to phone them back tomorrow and complain further, and if she still has no joy to say she will contact the Financial Ombudsman.

Thanks