Taxi vouchers from the South Australian transport subsidy scheme are no longer available. A new system using an id card issued by SATSS is being introduced in 2020. Go to their website link below.
Under the old scheme, a booklet of 80 vouchers could be re-issued every 6 months the new scheme does not state how many journeys can be undertaken?

South Australian Transport Subsidy Scheme (SATSS)
Phone: 1300 360 840
Email: DIT.SATSSenquiries@sa.gov.au
Web: https://www.satss.sa.gov.au/#members