Microwave oven control panel freezes

I have a built in Smeg microwave oven under warranty that cost over R10k. I cannot use it as the control panel freezes intermittently. I have had the panel replaced twice and faults persist. Model number is MFI 120 N2. I have requested a replacement or refund. Smeg not willing to listen. I'll avoid Smeg products in future as customer service is dire.