The Direct Debit Guarantee protects customers from payments taken in error. In the case of any incorrect or fraudulent payments, the payer is entitled to a full and immediate refund from their bank.
Organisations using the Direct Debit Scheme go through a careful vetting process before they're authorised, and are closely monitored by the banking industry. The efficiency and security of Direct Debit is monitored and protected by your own bank or building society.