Telkom insurance

Had a Phone contract which I paid off in 2018 but the company failed to close the insurance when I close the account,when I went back and asked why didn't they close everything I was told that I have to close it for myself,funny cause telkom is one that opened that insurance how does a customer cancel or close an insurance for themselves..well they tried to call the insurance guys but no answers so I decided to try too but no answer ,in 2020 around July called had luck they answered and said they will cancel but they didn't instead I still get calls and threats from Telkom attorneys that I owe them while I don't...