Unactioned request impacting my account payment

I submitted a debit order date change beginning of January. Got a confirmation email of the request from customer services only to realise that it wasn’t actioned. Called the support centre and they told me they are unable to update it now and that my debit order will still run and bounce. How do they expect me to accept such and allow a missed payment on my account which will impact my credit score when they were *********** and didn’t action my request on time. Not having it!!! Also over and above that was kept on hold for over 10 Mins by the agent.