Their letter makes no sense as it is template for a code 27 lowered footway, whereas the contravention you have is for code 28, where the carriageway has been raised to footway level.
There are two likely reasons for the PCN.
There is a table at the junction there and they consider the whole table is a pedestrian crossing.
Your car was blocking a driveway - that's OK if it's yours alone but it's a contravention if the driveway is shared.
