Disappointed with Hisense 42l mirror microwave

I’m really disappointed with the 42l mirror microwave which I bought a year ago and it has rust. How? I have a microwave at home which I bought in 2015 with no sign of rust. When I report this poor product I’m told about a 6 months warranty. Do you think I will ever buy your product again, no sorry this is unacceptable especially for the amount I paid for it. All my appliances are from Hisense so I know your quality but you don’t seem to see the is a problem with this.