(a) Upon payment by an agency, a business which has acquired under contract, property or services in connection with its contract with such agency from a subcontractor or supplier shall pay the subcontractor or supplier within thirty (30) days after receiving payment from the agency.
(b) Interest at the rate of one and one-half percent (1½%) per month shall accrue and is due any subcontractor or supplier who is not paid within thirty (30) days after the business receives payment from the agency, unless otherwise provided by contract between the agency and the business, or by contract between the business and the subcontractor or supplier. Interest begins to accrue on the thirty-first day at the rate specified in this subsection (b).