I'm never ever recommending this company to anyone, Im never going back!

I bought a nvr 16chanel from them, we opened it and turned out we were suppose to have bought a dvr 16 Chanel. When we realized that, I returned it within 7 days since it's been bought so that we can get the correct device for our cameras. When I got to the shop I was introduced to a lady named Marcia and explained to her that I would like to exchange she said not a problem at all and she took it. Then from the 14th june until now the 23rd june I wake to pictures of the product I took back to them saying it's broken they cannot take it and cannot refund me either. I was shocked because we only used it once and packaged it knowing it's not the right one we need. They are very rude and unprofessional, how do I damage a good like I have been using it for 5 years just by opening it ones? I'm so hurt R6000.00 down the drain please help me please. The pictures they sent is not the condition I gave them the product in. The receipt the they gave me is a job sheet, no amount is reflecting on it and no terms and conditions but I have the proof of payments because I used an EFT to make payment.