Home loans!!!

Absolutely bad experience!! A change of debit order date that leads to me being told I'm in arrears which to me was impossible. Called in and couldn't get an answer because the matter needed to be escalated and no I couldn't just speak to the right people myself. I was told to call in after a few days which I did and was told the fault was on their side and everything is sorted, only for my debit order to bounce today because there was insufficient funds as I was now charged extra on my debit order with no explanation!! So I'm liable for the bank charges, the extra amount on my debit order and a bad name!! Who will give me answers????