Telkom is the worst service ever!

I have signed up for a data sim contract with Telkom. I then cancelled within the 7 days when you are allowed to cancel, the consultant I spoke to confirmed that it has been cancelled. A few months later I see that I am in arrears, never received a statement from them, they tell me it's for the activation of the sim and service fees, WTH?????? I haven't even open the sim or used the data!!!! Worst service ever!!