Fnb doesn't want to assist me with debit order

Am dispute debit order for so many months, I went to one of their branch and spoke to several online consultants, all said I must change my card, so I wouldn't have problem with this debit order, I did that. For past two weeks the same company trying to debit twice and fnb keeps on charging me unpaid funds, I jst spoke to certain girl by the name of karin, she doesn't want to assist me.