Why is TFL knowingly committing fraud with ulez?

I own a st1300 motorbike. Every year of that motorbike is exempt from ulez. People got the COC certificates 6 years ago when ulez first came out.

So bob got a COC 6 years ago for a 2004 st1300 and gave it to TFL who exempted his bike.
3 years on mark goes on the TFL website with a 2004 st1300 puts in the reg and is told his bike is not exempt. so he creates an account and pays to use his bike every day. Three years late bob tells him his 2004 is exempt so mark contacts tfl for a refund for the last three years except tfl dont refund ulez.

Now times this by hundreds to thousands across cars and vans motorbikes etc. What a nice massive scam. TFL could update their database for the model and year of vehicle that are exempt but they wont
TFL could put your vehicle maybe exempt please contact the manufacturer but they wont
Instead TFL outright lie to you and tell you your vehicle is not exempt

I'm amazed they haven't been sued for knowingly taking incorrect payments often charging people for years. Maybe someone should create a ulez site that lists any vehicle that has been exempted by a COC certificate provided by the company who made the vehicle. It could be basic select brand, type then model.
Im wondering if a freedom of information request from tfl would provide every vehicle that has been exempted by providing a COC