You can purchase GAS from these places
Go to Binance
To provide users with more secure and convenient block-chain asset exchange services, polymerization of global high-quality block chain assets, is committed to creating a world-class block chain asset trading platform.
Go to Kucoin.com
The People's Exchange
Go to Poloniex
Welcome to Poloniex. We are a US-based digital asset exchange offering maximum security and advanced trading features.