I don’t have steam currently, but a possible workaround is that you can play on an internet browser, through game.cardhunter.com or through Kongregate. The only active forum user who would have authority to delete or ban your other accounts would be @Flaxative
...and therefore, you'll have more success writing support@cardhunter.com -- or at the very, very least, posting in the Support subforum instead of General Chat, although replies in that subforum to a deletion request will just send you to support@cardhunter.com anyway. $E^ b