Makro refuses to take back unsafe sports machinery

We bought an elliptical machine for exercise from Gale Armstrong at Makro Montague Gardens on the 29th April. Makro assembled the machine at the shop and we sent a truck to pick it up and deliver it to us in Kleinmond on 30th April. Makro DID NOT send the box with the assembled machine! The machine was not set up properly and they eventually sent someone to fix it in Kleinmond on the 7th. I used the machine and it caused terrible lower back and hip pain. I had to visit an Osteopath who advised me that research has shown that these machines are notorious for putting increased strain on your hips and lower back which inevitably causes the pain I was now experiencing. Gale Armstrong, the sports salesperson did not advise us that we should not exercise on this machine if we have bad hips and lower back problems. She was ONLY interested in the sale. We CANNOT use this machine so we decided to take the machine back. Makro DID NOT send the box with the machine when it was delivered and now they refuse to refund us or give us a credit note. The consumer protection act says we have 6 months to return unsafe goods! Makro's service to their loyal customers is shocking!