What is the penalty for a lawyer who takes advantage of a client's vulnerability by charging fees that he has not properly disclosed?

In Law Society of Upper Canada v. Yantha, 2015 ONLSTH 157, the lawyer took advantage of a client’s vulnerability by charging fees that he had not properly disclosed in advance, and without ever providing any explanation or accounting to the client. In ordering a three month suspension, the panel noted that whenever a lawyer takes advantage of a client’s vulnerability for their own benefit, it threatens to undermine public confidence in the legal profession, and that general deterrence requires that the penalty reflect this: see Yantha, above at para. 55.