So I took out additional data in August at a cost of £6. It was agreed on the phone this was a one off charge for August. I noticed last month (October) that Vodafone continued to take £6 for September and October. I phoned and was told they would correct their records. However, today I have noticed they have taken an extra £6 for November. I phoned again and this time asked them to refund 3 months for the extra data that I hadn't asked for. They have refused to refund the full £18 and have offered £11 only??? This is Vodafone's error and therefore I should get a full refund regardless of whether the additional data was used or not. Vodafone advertise on their website that this additional data is available and they would not continue to take the next month unless they have consent from the account holder. At no point was consent given. Sneaky behaviour by Vodafone - keep an eye on your bank statements people.