Received quote for 120 per month, better than cur...

Received quote for 120 per month, better than current supplier so switched. First payment asked for 350 . Asked why and was told as that bills were divided in 12, yes, but why such a big difference? Well, actually their financial year ends in April so you pay a higher amount if you switch during the winter. This was not at any point explained. Really faut spelen eneco. Not impressed and looking to switch.