Immediately debit order failed while funds left the Acc

Please make it make sense why I would make an immediate payment from my Capitec banking app to my FNB and have the funds not reflect. The next day I decide to call the bank only to be told the transaction failed and I should wait for 72 hours for the money to reflect bank in the account, meaning my debit order should bounce in the process while I wait the 72 hours and have a bad credit report to my name all because I should wait for 72hrs to have my money reflect back. Pathetic if you ask me