Won't start. Lights come on the dash and the car symbol flashes but when I turn the key I get nothing.

All of those things have been checked several times and arent the problem.

ok.if all that has been cleaned up,and shines like new and,tight,INCLUDING GROUNDS and the battery has a full charge on it>12.6 volts DC,then get a volt meter and a helper.set the volt meter on the 20 volt DC scale. have your helper turn the key to crank it while you check for battery voltage on the small wire going to the starter.if you have signal/voltage going to the starter solenoid (small wire),and does not attempt to spin the starter or the engine,then the starter is bad.if you have NO voltage/signal to the small wire on the starter solenoid,then suspect ignition switch is bad.