Horrific service at telkom

I have two data contracts with telkom, cancelled them in December 2017 but I am still being billed. Callled numerous times and exchange email but nothing it’s being done, instead upgrade department always call me offering me a new contract.

Their cancelling department is nonsense, it’s been 4 months now.

I really don’t know what to do, have been to the store nearby and the unfortunate part is that they don’t cancel it them selves.