Refund denied

I bought a bumber on their spares with no sample, told them that I am looking for a bumber for AMG, they gave us the one look like AMGs but they are not the same. The grill will not fit on the one they where providing. The panelbeater said it is not correct then we wanted to return it. They then refused to give our money back Which is R3500,00. I need help to get my money back