Autozone Vanderbijlpark refuses to refund

My brother bought a Clutch Master Cylinder for my car from Autozone Vanderbijlpark. I paid out my leave to be able to afford it. R1300.00. We weren't informed that we can't return the part We did not open the part it's still in original packaging and I have the receipt. Autozone refuses to refund me for the part. Autozone said they phoned the supplier who refuses to take back the part. The latter was proven to be untrue as I contacted the supplier who said no one phoned them to ask if they can return the part. My point is that this is a car part and not a consumable product that can expire on the shelf. How are they not able to refund me? I put R1300 into their business but now they are acting like I got the part for free! Why can't they refund me and keep the part in store? I need the refund urgently as I need other car parts and its my 2nd week walking to work (15km from work) and I work from 08h00 to 19h00. I live on the plots. I need to fix my car urgently and they are of no help. Just saying the supplier won't take the part back because it was ordered.

Again, why didn't they tell us that in the first place when ordering the part?