I know of no other way, and Turn 10 is difficult to contact. A big part if the problem is that they get swamped with emails whining about being banned or complaints against other players.
HighSeasHoMastrAuction house abuse is not the only way to get banned.
Did you mod your savegame?
Did you use the money glitch?
Did you post something on your storefront that was bannable?
T10 isn't in the business of banning people for "no reason" so forgive me if I'm a little bit skeptical...
But otherwise, no. There is no other way of contacting T10 that I am aware of.
Well it depends on the type of ban. If you only have an Auction House/Storefront ban then you should be able to race online, but if you have a full ban and are still able to race online then yes that is unusual.
What did the message in-game from T10 regarding the ban say?
HighSeasHoMastrWhat does it say when you attempt to access the Storefront or the Auction House?