LATE DELIVERY / WRONG IMPORTERS CODE

DHL has really let me down lately , you guys are suppose be a professional company that delivers on its promise, but instead lately all my goods are late and lays at the airport for days because DHL keep messing up my importers code. HOW MANY TIMES SHOULD I GIVE U THE CORRECT CODE BEFORE U GET IT RIGHT! Because of your incompetence I've now lost a lot business and money. when is DHL gonna get a simple thing like my importers code correct? Now its month end my goods were promised to be here at 10am and I get told again your driver has forgotten another parcel which isn't mine and has to go back with my parcel in his vehicle, this is unacceptable.