52. Unless for good and sufficient reason, a member may not cease to act on behalf of a client. The following shall, in particular, constitute good and sufficient reasons:
(1) loss of the client’s confidence;
(2) the fact that the member is placed in a conflict of interest situation or in circumstances where his professional independence could be questioned;
(3) inducement by the client to perform illegal, unjust or fraudulent acts;
(4) refusal by the client to recognize an obligation for the professional fees and expenses or, after being given reasonable notice, to pay an amount to the member to cover such fees and expenses.