VISA confirmed that I was using the correct information but that PM was attempting to use my OLD expiry date - despite me removing the card from the system and adding it back with updated information.
EXACT same problem. Clearly a bug in their interface. Even after deleting the card, PM still tries to use the old expiry of the card when submitting the new card. This is the most pathetic and stupid bug. How has PM not fixed this yet? it's been months!