Autobarn.com.au

Bought a spanner set. It was supposed to come with a range of sizes, including an 8mm and a 10 mm. When I got back home [100km round trip from store] I discovered the set I was sold came with 2x10mm spanners and no 8mm! The sales person failed to do his due diligence and properly check what he recommended I purchase. When I phoned the store the sales person said "don't use it; bring it back and we will replace the entire set". When I told them it was a 100km round trip they offered no other solution. So, I have to spend a few hours of my valuable time, and pay for petrol while I can't use the tools I paid for just to get the product they failed to ensure I was supposed to get?! I emailed headquarters and they said they would get the store to contact me, but this has not happened. I emailed headquarters again and no response so far. A single 8mm spanner will cost me about $11. I wonder if I should just send back one of the 10mm spanners and ask them to send me the 8mm one they failed to give me in the first place and also ask to be reimbursed the cost of postage?