Read it carefully and it probably says words along the lines of if you don't pay we'll recommend to our client to commence legal action, and also 'this is not subject to high court or bailiff action'. Got a few here that are the same 😁 - they're just shaking the tree in the hope some money falls out.
Having said that we have seen a couple of cases recently go further, one ending up with a claim, but as long as you don't ID the driver they have no where to go.