Without prejudice to any of the foregoing provisions of this Part of this Act, every solicitor for the time being practising on his own account without partners commits an offence against this Act if, without lawful justification or excuse, he—
(a) Fails to give a power of attorney in accordance with section 70 of this Act; or
(b) Revokes a power of attorney otherwise than in accordance with subsection (8) of that section; or
(c) Fails to give a notice under section 72 of this Act.