Telkom Acount service

Need some help here.... Telkom line was cancelled (due to terrible service) in the middle of June 2019. Understandable to pay the month and June 2019 but why must I for August and September. And just to confirm there was now service from 1 July to end September. Telkom wants me to pay for 3 months and they cannot give a reason why i must pay. And now almost a year later i get calls from rude Telkom workers telling me to pay or i will suffer. What must I do?