Cash build Garankuwa

I bought plumbing materials from Cash build in Ga-Rankuwa, Pretoria. The person who assisted started by writing wrong names and a wrong address on my quotation, basically he used someone else's details whom I don't know, when i asked about it they told me that it was a mistake but didn't change it. Then they included a gas stove on my quotation that costs about R460,and i only saw it when it was delivered. Tried to return it and was told that they don't refund, i need to take something else with the money. That money is alot and i don't understand why is it my fault now for a mistake that was done by their employee, i want my money back because i never ordered a stove, that person who wrote a stove should be the one paying for it not me