Being Billed after having line cancelled

I requested on the 17/09/2020 to have my Telkom home adsl cancelled. I recieved ref number: ***5 which reflects as resolved (sms recieved confirming this on the 14.10.2020). I have just recieved a bill for over r2000. What the F***. If the line is closed why do I owe you money? Reverse this and sort your accounting out.