We have to pay for their mistakes

On the 25th of July we requested to cancel our internet line which should have taken full effect in August yet September we had received yet another invoice for R235.60 (2 months after we requested our line to be cancelled) just to find out they never processed our cancellation. Now in october we get a statement saying we qualify to get R196 back???? where is the other R39.60. Our line was never active for 2 months but we have to pay?. after calling to discuss this not only did we receive a lot of disrespect but also had the phone put down on us