Telkom, your mistakes are costing me money!

For the 2nd time in the last 3 months Telkom has messed up my debit order and I was forced to incur additional bank charges because they debited me on the wrong date(the first time) and at the end of October they debited me from the wrong bank account(the second time). The first time I let the bank charges go however for this to happen a 2nd time is ridiculous. I am now forced to fit the bill for their errors. I tried to ask them for a refund for these bank charges and they refused. They are making stupid mistakes and customers have to pay for them.