A direct debit that wasn't mine got taken from my account and caused me to incurr 140pounds worth of charges, Vodafone took this direct debit and admitted it giving me a refund. I informed the bank but they said they couldn't refund the charges on my account. Who is liable for the charges? The bank or Vodafone??
Surely if the bank had paid out on a direct debit that you had not set up they are liable for the charges that you incurred. However, if you do have a direct debit with Vodaphone and they billed your account incorrectly the liability is theirs. It is not clear from your post exactly which happened.
Write a letter addressed to the branch manager of your bank. Explain the situation. Make sure you are straight to the point. You'll probably get a refund.
If Vodaphone has called for a direct debit that they shouldn't have, then they should be responsible for the bank charges not the bank. Do you have it in writing that Vodaphone accepted responsiblity over the mistake? I would pursue them for the additional charges. After all those fees were only incurred because of their error, not your mistake and not the bank. Go back to them and make them cough up. Threaten them with Watchdog if they dont.