You need to give client 30 days notice

I got my annual review letter on 08 May 2015 with an increased premium. The letter said that the premium will be effective from June. The increase was WAY too much and I requested for Virgin to have a relook at it. I then got a response saying that they cannot change it and that's what my premium will be going forward.<br> <br> On the 25th of May, my bank account was debited with the new premium. I do not understand why this has happened because as far as I know, my insurer is legally obliged to give me a 30 day notice of a price increase. 08 May to 25 May IS NOT 30 days notice.<br> <br> I want my money back and no longer want to be a client of Virgin Money Insurance.