It's difficult to exploit Direct Debits, as you are entitled to a full and immediate refund: https://www.directdebit.co.uk/DirectDebitExplained/pages/dir...

As far as I know, the ability to use direct debits is not given to everyone. You can't just start making direct debits just because you have a bank account.

My guess is that it's the same as elsewhere in the EU: Your bank will reverse the charge if you ask it to, the risk stays almost entirely with the payee/the payee's bank.

To do this, your business requires permission from your bank. If you abuse it, your bank will probably revoke your permission.