Walk Behind Lawn Mowers

I've had the lawnmower three years and I like it because it is light weight and easy to move. But every year I've had to take it in for repairs. The way the gas cap is designed, dirt can easily get in the fuel tank and then it gets in the engine. No matter how well the cap is secured, if you tip the lawn mower over then gas spills out. This mean dirt kicked up in the air gets in. Within a few months the first year the carburator had to be replaced because of dirt. The second year the motor was replaced. Now it's stopped again. I hate to take it in again when there is an obvious design flaw. I don't want to get a different brand but I may have to. Any suggestion on how to appeal to Husqvarna on this? I've written to them and I'm waiting on an answer.