LG Microwave damaged - mawr001463

I reported monday 7 dec 2015 my microwave not working. authorized agent to repair the microwave wrote report that it needs to be replaced as my microwave is rusted on the mechanical parts. NOTE: no rust inside my microwave, nor scratches or damaged on the outside. NO ONE FROM MAXICARE phones me back, i made 8 calls to the company to find out what is happening. spoke to: Merina, Mildred, Lea, Pshiralepso and at lat to Wilfred. telling that rust is not covered. in these calls i was told that i can prevent rust by leaving my micro's door open...yah right!!!!! been using a microwave for 30 years...no owners manual ever said that!!! i asked them to pull my claims history and see the numerous time this micro has gone in to the same repairer, and has now finally packed up. yet its thrown into my face that they dont cover rust. I CANNOT PREVENT THE RUST, must i take my micro apart and dry the mechanical side of it???? upon requesting the CEO and MD's details, they said they will get the operational manager to speak to me.... so he can tell me the same story....I want this microwave replaced!!!! Its an convectional LG Microwave, not some cheap product. sort his urgent.