Poor customer service

I did early upgrade 13 July 2018. The contract was supposed to end 13 July 2020 (24 months). I did another early upgrade in March 2019 of which I have a device penalty of which I agree. My problem is the penalty end date which is October 2020 not July 2020. I’ve phoned Telkom more than 10 times and went to different Telkom shops no one seem to know how to correct this in their system.