Unauthorised renewal of fixed term contract

In June 2018, I signed up for a 2 year contract including a mobile LTE router and data, at R139 per month. I stopped using it in 2019, and around November/December I called to cancel the contract. The cancellation fee ended up being higher than the value of the remaining payments for the contract, so in order to save money I allowed the contract to continue and expire as normal. July 2020 I see R40 debited from my account, which I immediately reverse because it was not authorised. I then receive a new invoice where the contract has inexplicably been converted to a month-to-month. I did NOT authorise this. No prior notice was given to me that this would occur. I then used the web form to cancel the contract "their way", which is currently in progress. And now with the august bill, I see that I am being charged R200 for the reversal. Well, lesson learned - NEVER GET A CONTRACT WITH TELKOM. I will be advising everyone I know to similarly avoid telkom.