For the most part, complaints are handled through the Bar. Unless something is a press-worthy scandal, they are promptly ignored by most Bars. The goal is to protect lawyers, not clients. A press-worthy case hurts lawyers. Normal scams are, well, what most lawyers do.
Suing a lawyer for malpractice in courts is very tough. There are all sorts of barriers. For example, let's say your lawyer fails to file legal paperwork on-time, and you lose a case. You can sue, but to collect damages:
* You have to show that in the alternative case, you would have won. The lawyer will argue you would have lost in either case.
* The case against your lawyer will likely impact your main case, and not in ways you like.
If your lawyer charges billable hours without actually working -- something which is standard practice among lawyers in my community -- you need to be able to prove that. It's the culture here:
* I've been to lunch with lawyers who bragged they were billing someone else for the time
* Lawyers routinely double-bill if e.g. handling client emails on a cell phone while in court for another client. ). How do you do that?
So it happens all the time, and I've gotten insane bills when nothing was done. You can't prove that in court, though. There's no case. And so on.