Wrong item refusing price difference

I am a highly disappointed with your service I bought from you a totai 4 burner heavy duty stove for my business for R3192 and I was a given an M. G brand stove which cost less than R2000 and the colour was incorrect as well. I then phoned your call centre and I was advised to take it back and the returns waiting days were a lot. I told them I made some adjustments on my food trailer to accommodate that stove and I asked for a price difference and they first came back and apologised and said I could keep the stove and for further assistance I must call the call centre and now they are refusing the price difference I don't know how many times I've called the returns department.