Telkom damaging my credit profile for their inability to resolve disputes

i had a router contract with telkom, last year June they debited my account for more than the agreed amount and i disputed the amount in July they called me an arranged to pay for the disputed amount plus charges which was debited from my account in August, telkom decided to disconnect their service with no communication whatsoever. 6 months later in march 2020 they started going into my account to debit way more than the contract amount with no communication what the amount is for and ever since i have been disputing this and querying this amounts with Telkom and during the lockdown period their excuse for not taking calls was the lockdown and then now i am been told is for rejection charges that accumulated from R200 to R2800 that they say i owe of which the rejection amount they are talking about was paid in August 2019. Now i am getting massages of notice of adverse listing - while i am here waiting for my matter to be resolved which i don't understand and also how can an account be accumulating charges whilst it is under query - it shows Telkom doesn't take us serious as customers