Debit before agreed date

This company does not respect the agreement reached with their clientele. Right now, they debited my account on the 15th when we agreed that they debit on the 20th. I have spoken to them about this malpractice but they seem not keen to change their ill habit. I am unable to visit my family for 26th December celebrations because budget took my petrol money and are not keen on refunding me. I believe that it is high time I leave them. It is not the first time . This is the third time. I am tired of this abuse.