1. Poloniex.com
voting list: https://poloniex.com/voting
add request url: https://poloniex.com/coinRequest
twitter: https://twitter.com/Poloniex
Email: contact@poloniex.com
Contact Poloniex owner: busoni
Follow their twitter and tweet them and asking to add MED market: @Poloniex
Post in Poloniex thread: https://bitcointalk.org/index.php?topic=420836

2. MintPal.com (So expensive to add MED)
voting list: https://www.mintpal.com/voting
twitter: https://twitter.com/MintPalExchange
Email: support@mintpal.com

3. bittrex.com
twitter: https[Suspicious link removed]xchange
Email: Support:Support@Zendesk
          Media: media@bittrex.com
Owner: Mr. Richie Lai
Email: richie@bittrex.com
twitter: https://twitter.com/richiela
Contact Bittrex owners here on Bitcointalk: richiela, Bittrex-Bill, Bittrex-Rami
Post in Bittrex thread: https://bitcointalk.org/index.php?topic=463202.0