Over Debted/Poor Service

DSTV is quick to suspend customer's service but don't refund funds when they over debit accounts. I called DSTV on the 21st to remove the Indian Bouquet & to amend the amount due for debit. I was told that it would be done as I called in time. My account was debited with incorrect amount causing my other debit order to return. Whose going to pay for the bank fees for the returned debit order???

Furthermore I need don't need to have a credit at DSTV but need my money refunded to me. I did what I was supposed to do which is to call 3 days before the debit order date. Yet I have been inconvenienced!!!! The billing system needs an upgrade !!!