Handling fee for cut tape

The worst decision ever to walk into the cornubia store. I purchased a soundbar and dvd player at the store. When I took it home I cut the tape on the box then changed my mind and decided to return the soundbar as I thought it was a bit too small for my lounge. Today morning when I took to return I was told the I would be charged a handling fee because the box was open. There was no tamper proof seal on box so the box could be resealed. I was told by the cashier that they had no cash and they will call me to give me my refund. When I returned to the store 4 hours later on my own without a call I questioned the manager and she said that if you go to buy a item and the box was open would you want it. So basically they are saying that me cutting a piece of tape costed me R240. But I was told if I take something else for the same value or more I won't have to pay the handling fee. I opted not to purchase anything more. Right now I just opened a dvd player purchased at same store and put in a brand new dvd bought yesterday and it is skipping and playing. There is also something loose inside the device. I will take to return tomorrow and expect a unsatisfactory reply from them. Worst customer service ever. And I don't think I will ever buy in this store again.