Gross incompetence from Telkom

I was with Telkom for my internet then during August it was so slow it was almost going backwards. So on the 31-08-18 I sent correspondence through their web site to cancel it I got 2 reference numbers from them ********** 3/ ********** 7. I checked on their website today they have loaded data onto my account although the account should of been closed on 30-09-18. I even returned the debit orders so I havn't paid them as I refuse to pay for bad service. So now it should be cancelled as well as I'm not paying them but they keep putting data on my closed account. This seems like gross incompetence.