Debit order

I have been back and forth with this institution regarding a debit order mandate I did not authorise for over a month now and I am being promised a call back all the time. Yesterday I had an internal transfer issue and I was told I can't get my money back. This poor safety for my money and poor service from a bank, I am really disappointed considering all the money they charge for banking with them. The staff is very condescending and not willing to assist.