Returned airfryer awaiting feedback for more than 2 mnths

We bought a AIM airfryer at PNP Waverley. It broke after few months. We returned it and explained that it just switches off after 5min. At first they didnt believe us. Then after more than a month we went back and then they say there is nothing wrong. We let them switch it on and after 5mins is says off. Then Jonathan - the person we dealt with - says o now he can explain to aim. It went back for 2nd time. We are waiting for 2 weeks again. They keep on saying they dont have feedback. I just want a new airfryer or my money back. Easy as that. And the manager you can't speak to. He is extremely rude.