Incorrect debit orders

I have just been debited today for a debit order that is supposed to go off on the 25th!! This all started in October when the premium increased with no notice. Not an annual increase, not a claims increase no changes were made. Just an increase out of nowhere. I then spoke to Cherine Theunissen who apologised for the error, reinstated my policy and advised I would get a debit order of a new lower premium come 25 November. That was all well and good and I was happy until I was debited on the 6th of November! That debit bounced and I got bank charges, Mare-lise Mundey assisted me with that and I got refunded the bank charge and again assured that I would only be debited on the 25th of November. This morning, when I check my account I see I have been debited. It's the 24th. I tried the bank so I can just reverse the debit but there's a 24 hour waiting period. I phone Oakhurst and I get told that it's ok because tomorrow they wont debit me. No it is not ok. I stipulated a debit date for a reason. It's unfair and inconsiderate and I'm worried at the kind of service I will receive if I ever need to submit a claim. This is incompetency and treating customers unfairly. Absolute *******.