The store wasn't very helpful

I purchased a mini trampoline with a 1 year warranty on 13 june of 2015 the trampoline broke and i went back to return it on the 1st of august 2015. They exchanged it for a new trampoline and it broke again and i went back again on 18th october 2015. This is now the 3rd time going back for the same product asking for my money back, this time they wont give me my money back they told me they must send it away and i must wait for 2 weeks. I am driving my petrol out and wasting my time in an effort to get my OWN money back but due to poor and riddiculous service i must go back after 2 weeks for the 4th time for the same product and same problem, is makro going to pay for my petrol and for my time? Makro is losing me as a customer. This is the poorest service i recieved from any consumer.