MFC CONFIRMATION MEANS NOTHING

DISGUSTING!!!! Please can someone tell me why now for the 2nd month in a row that the instalment has gone off, even after the debit order date has been changed to the 28th of the Month and I received confirmation that my next debit order will be the 28 December, only to get a surprise that it's gone off a week early with no funds in the account as yet!! The service is appalling, seriously MFC is going down the drain!