Homechoice specials are a ****

I ordered some product from homechoice which was on special for R699. The product was delivered and they sent a statement and according to the statement, the product was suddenly R1799. I callled them and they requested proof of what i was saying, i sent it and they said they'd get back to me within 48 hours, it's been weeks. They phone every day to sell products to me and when i explain the pending matter, they all just say "oh sorry" and hang up. I don't know what else to do.