Like taking your money twice and then you have to wait for refund

My debit order came back due to being paid late My debit order date was the 25 of every month I phone cell on the 29 November and made the arrangements to changes my debit order to the 1 st of every month I made a eft on the 29 nov to get my account up to date Mean while on the 1 st of December A debit amount went off my account I send 2 mails and was ignored I phone the call center and they said that going on here I asked for a refund as I cant afford paying a account twice if they dont advise me correctly I was advise that they took the debit order for the december invoice How can they just do that Hey i am the customer please note i will not wait for 7 working days for a refund Refund me asap