Telkom over charges people with their own mistakes

I am so disappointed with Telkom, in December they debited their money, the debit went through but then they reversed the money and charged me more money than i was supposed to pay, i lodged a complaint then they said the matter was fixed. January in the middle of the montg tbey debited R541, that was not our agreement because i did not owe them, i went to Telkom to lodge a complaint again then the matter was fixed as they said. January month end came they did not debit but on the 1st i took it upon myself and i paid on their Telkom app, now they say i am owing then R887 while i am supposed to pay 339. I feel like they give us the run arounds of not debiting or debiting then reversing the money just to charge people extra because of their mistakes ... I am so angry because i went to the store a couple of times and they sent me messages assuring me that the matter has been resolved when in actual fact nothing was resolved