Sad customer

I have cancelled my mobile contract online in March 2018, i live in Gansbaai so I have to drive to Herm**** to sort this out in a shop, but nothing is happening!! Telkom owe me R3000 maybe that's why, they don't want to pay my money back. Now they have charged me every month for a account that's cancelled, I have had enough now, I need the money?