service plan with toyota south africa

took a service plan with Toyota 1st up to 60 000 km then increased and amount debited increased but when I took my car for service they told me I don't have a service plan mine expired on 60 000km. when I ask why are they still debiting my account they said its a 24 months contract. they only helped me once since I took the plan for an amount of R1500 suddenly my contract expired. the was no communication about the expirer and they called me to increase the kilos and I agreed I'm still surprised of what am I still paying as was never even advised about the 24 months contract the only thing was told is up to 60 000km after I can increase of which I did and even the instalment increased as well.