ACT Fibernet — Late fee charges on Pre-paid service

Hi,
I did recharge plan for 3 months and it has been expired but they’ve not disconnected the service instead they have kept the service on and asking me to renew the plan and pay or else they would charge late fee.
I don’t understand this Pre-paid service-
It has to be a service which has to be given only after we’re paid right.
What Act doing is not fair it’s like forcing customer to opt and pay even they don’t want to.
Custome/consumer have right to start or stop the plan or recharge when required on pre-paid but continuing the service even when user don’t need and charging late fee is not acceptable.
Please do take action on such things which is being followed by Act