poorest service

have a router contract with mtn and for the first 2 months my data was loaded on the first day of the month the suddenly on the third month it was loaded on the 11th then i went to inquire at Woodmead mtn store they told me that mtn contracts are loaded on the 11th they have never ever loaded on the first day of the month i didnot want to argue because thats not what my contract say, boom 6 months later it is the 11nth and my data is not loaded!!!!! MTN knows the correct date to debit their money but not to load my data