I'd paid 1/3 of the policy already after just one month, still ended up owing THEM money when cancelling as they reclaim their commission from you (15%), and also charge a hefty £50 admin fee.
Even explaining the mix up with the email alias they weren't prepared to offer any sort of concession on those charges.
Lesson learnt and all that
but be warned Sky Insurance are one to avoid if you're the type to change car often!