Telkom fail to cancel contract and continue to bill R100 for 7 months

Good day

My cellphone contract came to an end in March 2021. After numerous calles received from Telekom to upgrade, I said I want to cancel my contract and that I don't want to upgrade.. I was told that a cancelation needs to be done online.. Why? When I go to a store to get a contract. In any case I logged the cancelation Now it's been 7months later and they still bill me R100 every month.. I have a cancelation case reference number ***8

I tried calling all the numbers I get online for telkom but the calls keep cutting off. I realy just want to cancel