17.—(1) A petroleum enforcement authority may revoke a licence where—
(a)there has been a change in circumstances so that the continued keeping of petrol in accordance with the conditions of the licence would create an unacceptable risk to the health or safety of any person; or
(b)a condition of the licence has been contravened.
(2) Where a licence is revoked, the licensee must return the licence to the petroleum enforcement authority within 28 days of the date of the revocation.