The OP in the linked case didn't disclose what they put in the appeal, but appeared to be along the lines of genuine user.
So you could try a 2 pronged appeal, 1 that you were a customer and 2 their notice is not POFA compliant to transfer liability to keeper. It might work; or it might not! What ever you do, don't disclose the driver's identity - even by accident, e.g. selecting a drop down box on their web form, or saying I did such and such - refer to drive in 3rd person.