Telkom - UNAUTHORISED CREDIT CHECK when CANCELLING landline

I finally got my fibre line installed last month (not Telkom) and upon trying to cancel my landline subscription I was told that there's a thirty (30) day cancellation period that I would still have to pay for. I responded saying that it was a complete ******* but it was fine so long as I was billed on a pro-rata basis for the month of March 2018. I received a bill at the beginning of the month for the full amount plus interest from February 2018. I phoned accounts and was told that I'd receive a final invoice amount to pay later in the month. It's the 26th and I'm still waiting, not knowing what the outstanding amount is. Hopefully I am informed before the hasty interest charges are slapped on again. What has really irritated me since though is that I see Telkom has run a credit check on me with the Credit Bureau WITHOUT MY AUTHORISATION. I get a report every month. WHY 1. was a credit check run on my name when CANCELLING my subscription?; and 2. do you at Telkom know that it directly and negatively impacts your credit score every time a credit check is run??? It takes 12 months for a credit check to be removed from your negative rating history. I have been unsuccessful in reaching anybody telephonically the whole of this morning via the multiple options after dialling 10210 to get an answer as to what's going on. I demand to know why the credit check was run on me without my consent, and what my outstanding balance is for final payment this month.