I'm not sure what you're looking for, but surely you supplied them with your IBAN details to authorise the direct debit. In turn your bank will record their originator code and other details on your monthly or quarterly statement against the relevant transactions (debits).
They had registered the details when account set. In February for some reason they deleted the DD and no payments went through since. When I asked they said something wrong my side. .. bank confirmed nothing wrong with my account. They have my bank details for mobile also. Unsure what issue led to them deleting the DD in February. ..