Recommendation for a microwave

I recently got RCA microwave (not sure exact model) but it is piece of shit. Even if i warm my food for 3 minute it doesn't warm properly. For example, yesterday i warmed pizza slice for 2 minutes. the cheez was bit warm but all the toppings were cold. I had another microwave before this (can't recall it's name) and never had issue with that.

Any recommendations. Would prefer something less than ~$350