You definitely can have it refunded back to your bank after they credit the Vodafone account. I got them to do that three times after multiple complaints. Two £100s (sync issues and trying to charge me the termination fee), and ~£20.
I joined them and got them to credit £50 for being crap which covered two months (£25mth), I then left after the first and got them to refund the remaining amount of credit and got two separate claims against them.
So I got a month and a bit for free and ~£220 from them messing up so much without actually giving them a penny.
Can recommend resolver.co.uk