I’m honestly disappointed by the service I’m getting from telkom ,I had a problem with my ADSL line ,reported it ,they came tried to fix it but failed I stopped paying from the 8th of August 2019 regardless I was still charged even even after my contract

I’m honestly disappointed by the service I’m getting from telkom ,I had a problem with my ADSL line ,reported it ,they came tried to fix it but failed I stopped paying from the 8th of August 2019 regardless I was still charged even even after my contract ended in March 2020 I’m still billed till now in September what do I do in this case cause when I ask they say my contract was renewed after March but they don’t know how