Early Debit Order

My December debit order came off today (17/12/20) for my personal loan. My contract with Capitec states my debit order date is only after the 25th. Not only was no permission granted for this transaction, but after taking the full amount my account has gone over into my overdraft meaning I will have incur fees with my own bank. The main reason I got rid off my previous loan at FNB was for exactly this reason. I'm now left with no money until pay day and extra fees - who gave Capitec the right to breach my contract?