Incorrect Billing!

I received my monthly statement and there was an extra amount noted of R1999. I called account for 2 days and there we no answer. I sent and email and was called by Veronica to advise that the R1999 was for outstanding hardware, hardware that we never collected when advised that they will collect it! I was told to drop off the hardware myself which I did on the 27th March and received the receipt that I had dropped it off. I emailed the delivery receipt to accounts and Veronica and the statement was still not amended! No the debit order was rejected because of an outstanding amount of R1999 for the hardware!... Please tell me if I can't phone to speak to someone to sort this out what needs to happen now or should I just cancel and go somewhere else?