Fix functionality of existing website -- 2

I have a basic website (www.freegascontest.com) that is intended to run multiple "gas contests". The user picks a city from a drop down menu and is redirected to a local weekly drawing. Those local merchants sponsor the Prize and give every participant special deals. I have installed RafflePress, but am willing to use https://wpsimplegiveaways.com/, or any other plugin to accomplish this process. It is slow from picking the City and is dumping everyone into one bucket. It has to seperate the contestants by City.