Return Nightmare

I ordered the same item two days in a row by mistake. When I received them both in different boxes a few days later, a logged a return for one, as I only needed one. During the return request process on the app, there was some kind of error and I was told to do it again. I did the return request again and when it finished, there were suddenly two returns logged. I decided to sort it out at the pick up point when I returned the one. I then installed the other one and was very disappointed with the quality. It was an HDMI switch and the picture kept going on and off. I decided to rather return both since there were already two return request generated. I got to the Waterkloof pick up point and they scanned both tiny boxes which I brought in a bigger box for convenience. A day later the one item was credited but not the other. I queried it with them and since then it has been a nightmare. I was asked if I took a picture as I handed each box to them!!? Then I was asked if the two boxes were together in the same box etc. Today I was told that I was lying and had only returned one item. Their email also referred to a picture from the store that was not in the email. Bear in mind this item cost R199. I have two separate emails from them with two different return numbers stating that the items had been successfully received by them. How on earth is that possible if I only returned one. I have bought lots and I mean lots of items from them and also returned quite a few with great success. I have never been so offended in my life.