I switched bank a few months ago. The new bank (First Direct) contacted all the companies that I have a Direct Debit with and told them to move the mandate from my old bank to the new one.
They all did it.
Apart from one:
They seem to have cancelled the old Direct Debit but not bothered to set up the new one.
Worse, rather than contacting me immediately when the last payment failed to go through, they cancelled my subscription and sent me a letter instead.
Which means this week's copy hasn't been delivered.