Better Business Bureau BBB BBB won't take my complaint seriously agains Kitchenaid Grand Rapids, Michigan

Purchased a range from Sears 4 years ago, it is a Kitchenaid gas range with self cleaning oven. We have had to have it repaired 4 times now, everytime you use the self-cleaning it fries out the circuit board and the thermostat.  I researched it online and found well over 50 people with the same model and they all have the same problem, and when you contact Kitchenaid they won't do anything about it and say it is not their problem. I contacted the BBB and they refuse to do anything about it, They need to be shut down, or there needs to be a government agency build to knock these companies down.