You haven't! This is just an authorisation charge to ensure that you have money available to charge your vehicle. Some banks may show this money as ‘pending’, but it won’t come out of your bank account. This process can sometimes take up to 7 days to return but it varies per bank.
You can top-up your Clenergy EV account with cash direct from your debit or credit card. This means you'll not be charged the £30 pre-authorisation charge.