Billing and payment error and harassment

Hello . . I am on a debit order and you underdebited me by R34.26 last month by mistake and as a result I am receiving repeated calls to all the numbers listed on my contract with an automated voice system asking me to pay the outstanding balance even after I reported your error to you and paid the balance out of frustration. Please sort this out immediately as we are all sick and tired of being called 3 or 4 times a day by your automated system.<br> <br> Thank you<br> <br> Robin