When I have reported black cab drivers misleading passengers, lying about pricing and regulations or bus drivers driving dangerously and being rude to everyone, TfL are totally uninterested. They give the impression that they know the scams operate and don't care. It's an interesting comparison with my Uber experience, which has been almost flawless and issues are usually fixed by Uber themselves promptly.
They flatly refused. They'd been told by a black cab driver the night before there was a 'strong possibility' they would get raped or robbed by 'foreign' drivers.