(a) A paid solicitor may not solicit contributions on behalf of a charitable organization unless the paid solicitor executes a written contract with the charitable organization that clearly states the respective obligations of the paid solicitor and the charitable organization, including
(1) a statement of the method to be used to calculate the compensation of the paid solicitor; the statement must include a reasonable estimate of the expenses, including the estimated compensation of the paid solicitor, to be incurred, directly or indirectly, by the charitable organization in connection with the solicitation;
(2) a statement of the charitable purpose to be described in the solicitation; and
(3) the percentage of the gross contributions that the charitable organization is to receive.
(b) A copy of the contract required by (a) of this section shall be filed with the department.