Telkom bad service and doesn’t refund what they owe you

We have had adsl line and cancelled it in 2016 Telkom hasn’t refunded us money yet which they say they can’t find any details showing they owe us and also we had lte router contract which we canceled in July 2019 for August 2019 they have deducted our account August and September 2019 and saying the Query is not complete as the case is still opened as we visited reds mall in Pretoria to cancel and apparently the agent haven’t done so