ACS Robbery on exchange request due to email miscommunication.

I had numerous back and forth email correspondence with a sales rep regarding an order which was fulfilled, however, the bottles received were not the expected design of bottle as my initial query was for square 200ml bottle or a round 200ml bottle, the bottles received were 100ml long cylindrical - completely not the same design at all and i did not realize this at any point in our correspondence. I have requested to exchange the bottles received for the original 200ml bottles but this company is now wanting to charge an extra R500 although I have advised that I will top up for the change in price between the 100ml and 200ml bottles. This is daylight robbery as I was clear about the type of bottle I am looking for and sent a screenshot from their website of it. Why am i being charged a fee when i want to do an exhange and not a refund??? Daylight robbery, i have not seen these products in person and images can be misleading, i should have the right to exchange without random additional charges made up