Vodacom is *****ing from clients

Vodacom double invoice you as a client, refuses to fix the bill, and threaten you if you do not pay the invoice, your line will be cut off. I don't have a problem with paying the bill, I have a problem that they invoice me double for the same number for the same month, and refuses to correct this, How can 1 number be invoice double for the same package same handset but only received one service. Vodacom is SA worst network provider