Game store canal walk sells second hand tvs

Good day. On friday I bought a tv at game canal walk at 14:59. They only had one left and the box was open and they said it is a new tv and they just opened it to show the customer and they did not take the tv. I paid and came back and asked the lady Chane to please put on the slip that the bix was open when I bought it and she said no they have to open the box instore to show me the screen is not cracked and it is working and it was never used before. I TOOOOOLD her I came from malmesbury and that it is far to drive to return it and she convinced me it is a new tv and there last one. Another gentlemen laught and said they need the sale. Took the tv went home and as I dont have dstv anymore went onto the netflix logg in. When it came up I saw 4 logg ins already on the account. They sold me a old tv, a SECOND HAND TV. I paid the price of a new tv for a second hand tv. How can a company so big do something like this? The tv is my sons tv and he stayed at home because he wanted to be surprised when he saw the tv and when he saw it he said daddy someone already used this tv. How the hel? I looked onto the customers settings and saw there email adress and I am in the process off contacting this person to find out why they returned the tv and when they bought it. I am not dropping this please contact me