Telkom does not want to cancel my contract with them

Telkom charged me R202.00 penalty for missing my monthly payment. This is the first time I miss a payment in the past 4 years being with them. The penalty amount charged is ridiculous. I am currently due for an upgrade and I do not think it is wise for me to renew my contract. Telkom please urgently cancel/discontinue my current contract with immediate effect. I do not want anything to do with Telkom anymore. I will settle my outstanding debt. For cancellation please note my ID number as: *** and my cell number for any further confirmation ***