Challenging decision from fines Victoria ($8k in fines)

Short version is I received a phone call from the sheriff regarding 2 speeding fines of "exceeding speed limit by under 10km/h" . Car is registered to my company. Fines notices were not received as would have been nominated to driver and paid as normal. Sheriff suggested to contact fines Victoria and ask for an extension to allow fines to be reset to infringement level so I tried to do that and failed. Then on advice from fines Victoria asked for a review of the infringements and after a 6 month deliberation that failed. The letter from fines Vic only gives 3 options. Pay the fine, apply for an extension to pay the fine or pay in installments. I still have not received any actual infringement notice , just the review result.

Can I challenge this review? Are there lawyers who specialise in this?