vodacom customer care line service is bad

I lost my phone so I did an upgrade on my vodacom contract for a samsung S8 that comes with a free J5 on promotion. When I got the phones and tried to do a simswap, I was told that my account is in arrears because Vodacom decided to charge me for the J5. Inquired about this, they said its a mistake they will resolve it. Its over a week now and nothing has been done except I'm being taken from pillar to post on their customer care line and to my surprise, the amount they say I'm arrears in keeps accumulating. I regret upgrading with them!