Debit order

My debit order is with Vodacom is set for 1sr of ea mth.Last month the Bank returned my debit order as it was only put through on the 3rd Aug. When I queried it at La Lucia Vodacom they informed me that it was due to is being over w/e. 1st was a Sat and Banks operate on a Sat. They couldn't take my payment it could only be done at Std Bank which I did the following Sat. This month they took off 299.02 instead of !99.50.The difference being the rtn fee. It is more than Bank charges for rtn of debit orders. I asked why they didn't inform me of the extra charges that would be debited so I could allow for it. I got a waffled answer.They increase the instalments without notifications and do debit without notifying me so I can make sure I have sufficient funds. Is this allowed. I asked to be refunded and the lady at customer service said she would put in a report that they accounts must phone me. She wasn't going to let them know that I wanted a refund of the R100.00. One doesn't seem to get anywhere with Customer Services so how does one get business resolved. I have been a long standing subscriber on only since renewal of contract in Dec have I had problems<br> Regards<br> Maria Marcu