Went to pay a 'new' bill online via bank transfer.
With my bank, you need your PINsentry unit to set up a new one. Once done, it remembers it for next time.
Pinsentry unit has a problem on the LCD screen - pixels missing so impossible to read the numbers. Checked the batteries which were fine - no surprise considering how little it has been used. But it wasn't likely to be the problem anyway.
So while logged on to my bank, decided to report it and ask for a new one. To actually talk to a human, you need your PIN sentry device...